<?xml version="1.0" encoding="US-ASCII" standalone="no"?>
    <!-- Field: Doc-Info; Name: Generator; Value: GoFiler Complete; Version: 5.25b -->
    <!-- Field: Doc-Info; Name: VendorURI; Value: https://www.novaworks.com -->
    <!-- Field: Doc-Info; Name: Status; Value: 0x00000000 -->
<link:linkbase xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:link="http://www.xbrl.org/2003/linkbase" xmlns:xbrldt="http://xbrl.org/2005/xbrldt" xmlns:xbrli="http://www.xbrl.org/2003/instance" xsi:schemaLocation="http://www.xbrl.org/2003/linkbase http://www.xbrl.org/2003/xbrl-linkbase-2003-12-31.xsd">
    <link:roleRef roleURI="http://genenta.com/role/Cover" xlink:href="gnta-20241231.xsd#Cover" xlink:type="simple" />
    <link:roleRef roleURI="http://genenta.com/role/StatementsOfOperationsAndComprehensiveLoss" xlink:href="gnta-20241231.xsd#StatementsOfOperationsAndComprehensiveLoss" xlink:type="simple" />
    <link:roleRef roleURI="http://genenta.com/role/BalanceSheets" xlink:href="gnta-20241231.xsd#BalanceSheets" xlink:type="simple" />
    <link:roleRef roleURI="http://genenta.com/role/BalanceSheetsParenthetical" xlink:href="gnta-20241231.xsd#BalanceSheetsParenthetical" xlink:type="simple" />
    <link:roleRef roleURI="http://genenta.com/role/StatementOfChangesInShareholdersEquity" xlink:href="gnta-20241231.xsd#StatementOfChangesInShareholdersEquity" xlink:type="simple" />
    <link:roleRef roleURI="http://genenta.com/role/StatementsOfCashFlows" xlink:href="gnta-20241231.xsd#StatementsOfCashFlows" xlink:type="simple" />
    <link:roleRef roleURI="http://xbrl.sec.gov/cyd/role/CybersecurityRiskManagementAndStrategyDisclosure" xlink:href="https://xbrl.sec.gov/cyd/2024/cyd-2024.xsd#CybersecurityRiskManagementAndStrategyDisclosure" xlink:type="simple" />
    <link:roleRef roleURI="http://xbrl.sec.gov/cyd/role/MaterialCybersecurityIncidentDisclosure" xlink:href="https://xbrl.sec.gov/cyd/2024/cyd-2024.xsd#MaterialCybersecurityIncidentDisclosure" xlink:type="simple" />
    <link:roleRef roleURI="http://genenta.com/role/NatureOfBusinessAndHistory" xlink:href="gnta-20241231.xsd#NatureOfBusinessAndHistory" xlink:type="simple" />
    <link:roleRef roleURI="http://genenta.com/role/SummaryOfSignificantAccountingPolicies" xlink:href="gnta-20241231.xsd#SummaryOfSignificantAccountingPolicies" xlink:type="simple" />
    <link:roleRef roleURI="http://genenta.com/role/ResearchAndDevelopment" xlink:href="gnta-20241231.xsd#ResearchAndDevelopment" xlink:type="simple" />
    <link:roleRef roleURI="http://genenta.com/role/GeneralAndAdministrative" xlink:href="gnta-20241231.xsd#GeneralAndAdministrative" xlink:type="simple" />
    <link:roleRef roleURI="http://genenta.com/role/IncomeTaxes" xlink:href="gnta-20241231.xsd#IncomeTaxes" xlink:type="simple" />
    <link:roleRef roleURI="http://genenta.com/role/PrepaidExpensesAndOtherCurrentAssets" xlink:href="gnta-20241231.xsd#PrepaidExpensesAndOtherCurrentAssets" xlink:type="simple" />
    <link:roleRef roleURI="http://genenta.com/role/FixedAssetsNet" xlink:href="gnta-20241231.xsd#FixedAssetsNet" xlink:type="simple" />
    <link:roleRef roleURI="http://genenta.com/role/Non-currentAssetsRightOfUseRou" xlink:href="gnta-20241231.xsd#Non-currentAssetsRightOfUseRou" xlink:type="simple" />
    <link:roleRef roleURI="http://genenta.com/role/OtherNon-currentAssets" xlink:href="gnta-20241231.xsd#OtherNon-currentAssets" xlink:type="simple" />
    <link:roleRef roleURI="http://genenta.com/role/RetirementBenefitObligation" xlink:href="gnta-20241231.xsd#RetirementBenefitObligation" xlink:type="simple" />
    <link:roleRef roleURI="http://genenta.com/role/ShareholdersEquity" xlink:href="gnta-20241231.xsd#ShareholdersEquity" xlink:type="simple" />
    <link:roleRef roleURI="http://genenta.com/role/Share-basedCompensation" xlink:href="gnta-20241231.xsd#Share-basedCompensation" xlink:type="simple" />
    <link:roleRef roleURI="http://genenta.com/role/AccumulatedOtherComprehensiveIncome" xlink:href="gnta-20241231.xsd#AccumulatedOtherComprehensiveIncome" xlink:type="simple" />
    <link:roleRef roleURI="http://genenta.com/role/RelatedParties" xlink:href="gnta-20241231.xsd#RelatedParties" xlink:type="simple" />
    <link:roleRef roleURI="http://genenta.com/role/CommitmentsAndContingencies" xlink:href="gnta-20241231.xsd#CommitmentsAndContingencies" xlink:type="simple" />
    <link:roleRef roleURI="http://genenta.com/role/SubsequentEvents" xlink:href="gnta-20241231.xsd#SubsequentEvents" xlink:type="simple" />
    <link:roleRef roleURI="http://genenta.com/role/SummaryOfSignificantAccountingPoliciesPolicies" xlink:href="gnta-20241231.xsd#SummaryOfSignificantAccountingPoliciesPolicies" xlink:type="simple" />
    <link:roleRef roleURI="http://genenta.com/role/SummaryOfSignificantAccountingPoliciesTables" xlink:href="gnta-20241231.xsd#SummaryOfSignificantAccountingPoliciesTables" xlink:type="simple" />
    <link:roleRef roleURI="http://genenta.com/role/IncomeTaxesTables" xlink:href="gnta-20241231.xsd#IncomeTaxesTables" xlink:type="simple" />
    <link:roleRef roleURI="http://genenta.com/role/PrepaidExpensesAndOtherCurrentAssetsTables" xlink:href="gnta-20241231.xsd#PrepaidExpensesAndOtherCurrentAssetsTables" xlink:type="simple" />
    <link:roleRef roleURI="http://genenta.com/role/FixedAssetsNetTables" xlink:href="gnta-20241231.xsd#FixedAssetsNetTables" xlink:type="simple" />
    <link:roleRef roleURI="http://genenta.com/role/OtherNon-currentAssetsTables" xlink:href="gnta-20241231.xsd#OtherNon-currentAssetsTables" xlink:type="simple" />
    <link:roleRef roleURI="http://genenta.com/role/Share-basedCompensationTables" xlink:href="gnta-20241231.xsd#Share-basedCompensationTables" xlink:type="simple" />
    <link:roleRef roleURI="http://genenta.com/role/AccumulatedOtherComprehensiveIncomeTables" xlink:href="gnta-20241231.xsd#AccumulatedOtherComprehensiveIncomeTables" xlink:type="simple" />
    <link:roleRef roleURI="http://genenta.com/role/RelatedPartiesTables" xlink:href="gnta-20241231.xsd#RelatedPartiesTables" xlink:type="simple" />
    <link:roleRef roleURI="http://genenta.com/role/CommitmentsAndContingenciesTables" xlink:href="gnta-20241231.xsd#CommitmentsAndContingenciesTables" xlink:type="simple" />
    <link:roleRef roleURI="http://genenta.com/role/NatureOfBusinessAndHistoryDetailsNarrative" xlink:href="gnta-20241231.xsd#NatureOfBusinessAndHistoryDetailsNarrative" xlink:type="simple" />
    <link:roleRef roleURI="http://genenta.com/role/ScheduleOfCashAndCashEquivalentsDetails" xlink:href="gnta-20241231.xsd#ScheduleOfCashAndCashEquivalentsDetails" xlink:type="simple" />
    <link:roleRef roleURI="http://genenta.com/role/ScheduleOfMarketableSecuritiesDetails" xlink:href="gnta-20241231.xsd#ScheduleOfMarketableSecuritiesDetails" xlink:type="simple" />
    <link:roleRef roleURI="http://genenta.com/role/ScheduleOfFairValuesDueToShort-termNatureOfAssetsAndLiabilitiesDetails" xlink:href="gnta-20241231.xsd#ScheduleOfFairValuesDueToShort-termNatureOfAssetsAndLiabilitiesDetails" xlink:type="simple" />
    <link:roleRef roleURI="http://genenta.com/role/SummaryOfSignificantAccountingPoliciesDetailsNarrative" xlink:href="gnta-20241231.xsd#SummaryOfSignificantAccountingPoliciesDetailsNarrative" xlink:type="simple" />
    <link:roleRef roleURI="http://genenta.com/role/ScheduleOfEffectiveIncomeTaxRateReconciliationDetails" xlink:href="gnta-20241231.xsd#ScheduleOfEffectiveIncomeTaxRateReconciliationDetails" xlink:type="simple" />
    <link:roleRef roleURI="http://genenta.com/role/ScheduleOfDeferredTaxAssetsDetails" xlink:href="gnta-20241231.xsd#ScheduleOfDeferredTaxAssetsDetails" xlink:type="simple" />
    <link:roleRef roleURI="http://genenta.com/role/ScheduleOfTaxLossCarryforwardsExpireDetails" xlink:href="gnta-20241231.xsd#ScheduleOfTaxLossCarryforwardsExpireDetails" xlink:type="simple" />
    <link:roleRef roleURI="http://genenta.com/role/IncomeTaxesDetailsNarrative" xlink:href="gnta-20241231.xsd#IncomeTaxesDetailsNarrative" xlink:type="simple" />
    <link:roleRef roleURI="http://genenta.com/role/ScheduleOfPrepaidExpensesAndOtherCurrentAssetsDetails" xlink:href="gnta-20241231.xsd#ScheduleOfPrepaidExpensesAndOtherCurrentAssetsDetails" xlink:type="simple" />
    <link:roleRef roleURI="http://genenta.com/role/PrepaidExpensesAndOtherCurrentAssetsDetailsNarrative" xlink:href="gnta-20241231.xsd#PrepaidExpensesAndOtherCurrentAssetsDetailsNarrative" xlink:type="simple" />
    <link:roleRef roleURI="http://genenta.com/role/ScheduleOfFixedAssetsnetDetails" xlink:href="gnta-20241231.xsd#ScheduleOfFixedAssetsnetDetails" xlink:type="simple" />
    <link:roleRef roleURI="http://genenta.com/role/Non-currentAssetsRightOfUseRouDetailsNarrative" xlink:href="gnta-20241231.xsd#Non-currentAssetsRightOfUseRouDetailsNarrative" xlink:type="simple" />
    <link:roleRef roleURI="http://genenta.com/role/ScheduleOfOtherNon-currentAssetsDetails" xlink:href="gnta-20241231.xsd#ScheduleOfOtherNon-currentAssetsDetails" xlink:type="simple" />
    <link:roleRef roleURI="http://genenta.com/role/OtherNon-currentAssetsDetailsNarrative" xlink:href="gnta-20241231.xsd#OtherNon-currentAssetsDetailsNarrative" xlink:type="simple" />
    <link:roleRef roleURI="http://genenta.com/role/RetirementBenefitObligationDetailsNarrative" xlink:href="gnta-20241231.xsd#RetirementBenefitObligationDetailsNarrative" xlink:type="simple" />
    <link:roleRef roleURI="http://genenta.com/role/ShareholdersEquityDetailsNarrative" xlink:href="gnta-20241231.xsd#ShareholdersEquityDetailsNarrative" xlink:type="simple" />
    <link:roleRef roleURI="http://genenta.com/role/ScheduleOfOutstandingStockOptionsDetails" xlink:href="gnta-20241231.xsd#ScheduleOfOutstandingStockOptionsDetails" xlink:type="simple" />
    <link:roleRef roleURI="http://genenta.com/role/ScheduleOfShareBasedCompensationExpensesDetails" xlink:href="gnta-20241231.xsd#ScheduleOfShareBasedCompensationExpensesDetails" xlink:type="simple" />
    <link:roleRef roleURI="http://genenta.com/role/Share-basedCompensationDetailsNarrative" xlink:href="gnta-20241231.xsd#Share-basedCompensationDetailsNarrative" xlink:type="simple" />
    <link:roleRef roleURI="http://genenta.com/role/ScheduleOfAccumulatedOtherComprehensiveIncomeDetails" xlink:href="gnta-20241231.xsd#ScheduleOfAccumulatedOtherComprehensiveIncomeDetails" xlink:type="simple" />
    <link:roleRef roleURI="http://genenta.com/role/AccumulatedOtherComprehensiveIncomeDetailsNarrative" xlink:href="gnta-20241231.xsd#AccumulatedOtherComprehensiveIncomeDetailsNarrative" xlink:type="simple" />
    <link:roleRef roleURI="http://genenta.com/role/ScheduleOfThirdPartyAndRelatedPartyExpensesDetails" xlink:href="gnta-20241231.xsd#ScheduleOfThirdPartyAndRelatedPartyExpensesDetails" xlink:type="simple" />
    <link:roleRef roleURI="http://genenta.com/role/ScheduleOfThirdPartyAndGeneralAndAdministrativeExpensesDetails" xlink:href="gnta-20241231.xsd#ScheduleOfThirdPartyAndGeneralAndAdministrativeExpensesDetails" xlink:type="simple" />
    <link:roleRef roleURI="http://genenta.com/role/ScheduleOfAccountsPayableToRelatedPartiesDetails" xlink:href="gnta-20241231.xsd#ScheduleOfAccountsPayableToRelatedPartiesDetails" xlink:type="simple" />
    <link:roleRef roleURI="http://genenta.com/role/ScheduleOfAccruedExpensesToRelatedPartiesDetails" xlink:href="gnta-20241231.xsd#ScheduleOfAccruedExpensesToRelatedPartiesDetails" xlink:type="simple" />
    <link:roleRef roleURI="http://genenta.com/role/RelatedPartiesDetailsNarrative" xlink:href="gnta-20241231.xsd#RelatedPartiesDetailsNarrative" xlink:type="simple" />
    <link:roleRef roleURI="http://genenta.com/role/ScheduleOfCompanyObligationsByContractualMaturityDetails" xlink:href="gnta-20241231.xsd#ScheduleOfCompanyObligationsByContractualMaturityDetails" xlink:type="simple" />
    <link:roleRef roleURI="http://genenta.com/role/CommitmentsAndContingenciesDetailsNarrative" xlink:href="gnta-20241231.xsd#CommitmentsAndContingenciesDetailsNarrative" xlink:type="simple" />
    <link:roleRef roleURI="http://genenta.com/role/SubsequentEventsDetailsNarrative" xlink:href="gnta-20241231.xsd#SubsequentEventsDetailsNarrative" xlink:type="simple" />
    <link:roleRef roleURI="http://xbrl.sec.gov/ecd/role/PvpDisclosureWithAdditionalMeasures" xlink:href="https://xbrl.sec.gov/ecd/2024/ecd-2024.xsd#PvpDisclosureWithAdditionalMeasures" xlink:type="simple" />
    <link:roleRef roleURI="http://xbrl.sec.gov/ecd/role/PvpTable" xlink:href="https://xbrl.sec.gov/ecd/2024/ecd-2024.xsd#PvpTable" xlink:type="simple" />
    <link:roleRef roleURI="http://xbrl.sec.gov/ecd/role/PvpAdjustmentsToCompensation" xlink:href="https://xbrl.sec.gov/ecd/2024/ecd-2024.xsd#PvpAdjustmentsToCompensation" xlink:type="simple" />
    <link:roleRef roleURI="http://xbrl.sec.gov/ecd/role/TabularListsByExecutiveCategory" xlink:href="https://xbrl.sec.gov/ecd/2024/ecd-2024.xsd#TabularListsByExecutiveCategory" xlink:type="simple" />
    <link:roleRef roleURI="http://xbrl.sec.gov/ecd/role/TabularListMeasures" xlink:href="https://xbrl.sec.gov/ecd/2024/ecd-2024.xsd#TabularListMeasures" xlink:type="simple" />
    <link:roleRef roleURI="http://xbrl.sec.gov/ecd/role/PvpMeasures" xlink:href="https://xbrl.sec.gov/ecd/2024/ecd-2024.xsd#PvpMeasures" xlink:type="simple" />
    <link:roleRef roleURI="http://xbrl.sec.gov/ecd/role/PvpExecutiveCategoriesOnly" xlink:href="https://xbrl.sec.gov/ecd/2024/ecd-2024.xsd#PvpExecutiveCategoriesOnly" xlink:type="simple" />
    <link:roleRef roleURI="http://xbrl.sec.gov/ecd/role/PvpAdjustmentsOnly" xlink:href="https://xbrl.sec.gov/ecd/2024/ecd-2024.xsd#PvpAdjustmentsOnly" xlink:type="simple" />
    <link:roleRef roleURI="http://xbrl.sec.gov/ecd/role/IndividualsOnly" xlink:href="https://xbrl.sec.gov/ecd/2024/ecd-2024.xsd#IndividualsOnly" xlink:type="simple" />
    <link:roleRef roleURI="http://xbrl.sec.gov/ecd/AwardTypeOnly" xlink:href="https://xbrl.sec.gov/ecd/2024/ecd-2024.xsd#AwardTypeOnly" xlink:type="simple" />
    <link:roleRef roleURI="http://xbrl.sec.gov/ecd/role/TradingArrangementsOnly" xlink:href="https://xbrl.sec.gov/ecd/2024/ecd-2024.xsd#TradingArrangmentsOnly" xlink:type="simple" />
    <link:roleRef roleURI="http://xbrl.sec.gov/ecd/role/ForgoneRecoveries" xlink:href="https://xbrl.sec.gov/ecd/2024/ecd-2024.xsd#ForgoneRecoveries" xlink:type="simple" />
    <link:roleRef roleURI="http://xbrl.sec.gov/ecd/role/OutstandingRecoveries" xlink:href="https://xbrl.sec.gov/ecd/2024/ecd-2024.xsd#OutstandingRecoveries" xlink:type="simple" />
    <link:roleRef roleURI="http://xbrl.sec.gov/ecd/role/AwardsCloseToMnpiDisc" xlink:href="https://xbrl.sec.gov/ecd/2024/ecd-2024.xsd#AwardsCloseToMnpiDisc" xlink:type="simple" />
    <link:roleRef roleURI="http://xbrl.sec.gov/ecd/role/InsiderTradingArrangementsByInd" xlink:href="https://xbrl.sec.gov/ecd/2024/ecd-2024.xsd#InsiderTradingArrangemenstByInd" xlink:type="simple" />
    <link:roleRef roleURI="http://xbrl.sec.gov/ecd/role/Defaults" xlink:href="https://xbrl.sec.gov/ecd/2024/ecd-2024.xsd#Defaults" xlink:type="simple" />
    <link:arcroleRef xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#hypercube-dimension" arcroleURI="http://xbrl.org/int/dim/arcrole/hypercube-dimension" />
    <link:arcroleRef xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#dimension-domain" arcroleURI="http://xbrl.org/int/dim/arcrole/dimension-domain" />
    <link:arcroleRef xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#domain-member" arcroleURI="http://xbrl.org/int/dim/arcrole/domain-member" />
    <link:arcroleRef xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#all" arcroleURI="http://xbrl.org/int/dim/arcrole/all" />
    <link:arcroleRef xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#notAll" arcroleURI="http://xbrl.org/int/dim/arcrole/notAll" />
    <link:arcroleRef xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#dimension-default" arcroleURI="http://xbrl.org/int/dim/arcrole/dimension-default" />
    <link:definitionLink xlink:type="extended" xlink:role="http://genenta.com/role/Cover" xlink:title="00000001 - Document - Cover">
      <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_EntityAddressesLineItems" xlink:label="loc_deiEntityAddressesLineItems" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_EntityAddressesTable" xlink:label="loc_deiEntityAddressesTable" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xbrldt:contextElement="segment" xlink:from="loc_deiEntityAddressesLineItems" xlink:to="loc_deiEntityAddressesTable" xlink:type="arc" order="10" xbrldt:closed="true" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_EntityAddressesAddressTypeAxis" xlink:label="loc_deiEntityAddressesAddressTypeAxis" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_deiEntityAddressesTable" xlink:to="loc_deiEntityAddressesAddressTypeAxis" xlink:type="arc" order="1" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_AddressTypeDomain" xlink:label="loc_deiAddressTypeDomain" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_deiEntityAddressesAddressTypeAxis" xlink:to="loc_deiAddressTypeDomain" xlink:type="arc" order="20" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_AddressTypeDomain" xlink:label="loc_deiAddressTypeDomain_10" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xbrldt:contextElement="segment" xlink:from="loc_deiEntityAddressesAddressTypeAxis" xlink:to="loc_deiAddressTypeDomain_10" xlink:type="arc" order="30" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_BusinessContactMember" xlink:label="loc_deiBusinessContactMember_10" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_deiAddressTypeDomain" xlink:to="loc_deiBusinessContactMember_10" xlink:type="arc" order="11" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StatementClassOfStockAxis" xlink:label="loc_us-gaapStatementClassOfStockAxis" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_deiEntityAddressesTable" xlink:to="loc_us-gaapStatementClassOfStockAxis" xlink:type="arc" order="2" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ClassOfStockDomain" xlink:label="loc_us-gaapClassOfStockDomain" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaapStatementClassOfStockAxis" xlink:to="loc_us-gaapClassOfStockDomain" xlink:type="arc" order="20" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ClassOfStockDomain" xlink:label="loc_us-gaapClassOfStockDomain_10" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xbrldt:contextElement="segment" xlink:from="loc_us-gaapStatementClassOfStockAxis" xlink:to="loc_us-gaapClassOfStockDomain_10" xlink:type="arc" order="30" />
      <link:loc xlink:type="locator" xlink:href="gnta-20241231.xsd#GNTA_AmericanDepositarySharesEachAmericanDepositaryShareRepresentingOneOrdinaryShareMember" xlink:label="loc_GNTAAmericanDepositarySharesEachAmericanDepositaryShareRepresentingOneOrdinaryShareMember_20" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapClassOfStockDomain" xlink:to="loc_GNTAAmericanDepositarySharesEachAmericanDepositaryShareRepresentingOneOrdinaryShareMember_20" xlink:type="arc" order="21" />
      <link:loc xlink:type="locator" xlink:href="gnta-20241231.xsd#GNTA_OrdinarySharesNoParValueMember" xlink:label="loc_GNTAOrdinarySharesNoParValueMember_30" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapClassOfStockDomain" xlink:to="loc_GNTAOrdinarySharesNoParValueMember_30" xlink:type="arc" order="31" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_DocumentType" xlink:label="loc_deiDocumentType_60" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_deiEntityAddressesLineItems" xlink:to="loc_deiDocumentType_60" xlink:type="arc" order="0" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_AmendmentFlag" xlink:label="loc_deiAmendmentFlag_60" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_deiEntityAddressesLineItems" xlink:to="loc_deiAmendmentFlag_60" xlink:type="arc" order="1" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_AmendmentDescription" xlink:label="loc_deiAmendmentDescription_60" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_deiEntityAddressesLineItems" xlink:to="loc_deiAmendmentDescription_60" xlink:type="arc" order="2" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_DocumentRegistrationStatement" xlink:label="loc_deiDocumentRegistrationStatement_60" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_deiEntityAddressesLineItems" xlink:to="loc_deiDocumentRegistrationStatement_60" xlink:type="arc" order="3" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_DocumentAnnualReport" xlink:label="loc_deiDocumentAnnualReport_60" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_deiEntityAddressesLineItems" xlink:to="loc_deiDocumentAnnualReport_60" xlink:type="arc" order="4" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_DocumentQuarterlyReport" xlink:label="loc_deiDocumentQuarterlyReport_60" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_deiEntityAddressesLineItems" xlink:to="loc_deiDocumentQuarterlyReport_60" xlink:type="arc" order="5" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_DocumentTransitionReport" xlink:label="loc_deiDocumentTransitionReport_60" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_deiEntityAddressesLineItems" xlink:to="loc_deiDocumentTransitionReport_60" xlink:type="arc" order="6" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_DocumentShellCompanyReport" xlink:label="loc_deiDocumentShellCompanyReport_60" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_deiEntityAddressesLineItems" xlink:to="loc_deiDocumentShellCompanyReport_60" xlink:type="arc" order="7" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_DocumentShellCompanyEventDate" xlink:label="loc_deiDocumentShellCompanyEventDate_60" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_deiEntityAddressesLineItems" xlink:to="loc_deiDocumentShellCompanyEventDate_60" xlink:type="arc" order="8" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_DocumentPeriodStartDate" xlink:label="loc_deiDocumentPeriodStartDate_60" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_deiEntityAddressesLineItems" xlink:to="loc_deiDocumentPeriodStartDate_60" xlink:type="arc" order="9" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_DocumentPeriodEndDate" xlink:label="loc_deiDocumentPeriodEndDate_60" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_deiEntityAddressesLineItems" xlink:to="loc_deiDocumentPeriodEndDate_60" xlink:type="arc" order="10" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_DocumentFiscalPeriodFocus" xlink:label="loc_deiDocumentFiscalPeriodFocus_60" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_deiEntityAddressesLineItems" xlink:to="loc_deiDocumentFiscalPeriodFocus_60" xlink:type="arc" order="11" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_DocumentFiscalYearFocus" xlink:label="loc_deiDocumentFiscalYearFocus_60" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_deiEntityAddressesLineItems" xlink:to="loc_deiDocumentFiscalYearFocus_60" xlink:type="arc" order="12" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_CurrentFiscalYearEndDate" xlink:label="loc_deiCurrentFiscalYearEndDate_60" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_deiEntityAddressesLineItems" xlink:to="loc_deiCurrentFiscalYearEndDate_60" xlink:type="arc" order="13" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_EntityFileNumber" xlink:label="loc_deiEntityFileNumber_60" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_deiEntityAddressesLineItems" xlink:to="loc_deiEntityFileNumber_60" xlink:type="arc" order="14" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_EntityRegistrantName" xlink:label="loc_deiEntityRegistrantName_60" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_deiEntityAddressesLineItems" xlink:to="loc_deiEntityRegistrantName_60" xlink:type="arc" order="15" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_EntityCentralIndexKey" xlink:label="loc_deiEntityCentralIndexKey_60" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_deiEntityAddressesLineItems" xlink:to="loc_deiEntityCentralIndexKey_60" xlink:type="arc" order="16" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_EntityPrimarySicNumber" xlink:label="loc_deiEntityPrimarySicNumber_60" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_deiEntityAddressesLineItems" xlink:to="loc_deiEntityPrimarySicNumber_60" xlink:type="arc" order="17" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_EntityTaxIdentificationNumber" xlink:label="loc_deiEntityTaxIdentificationNumber_60" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_deiEntityAddressesLineItems" xlink:to="loc_deiEntityTaxIdentificationNumber_60" xlink:type="arc" order="18" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_EntityIncorporationStateCountryCode" xlink:label="loc_deiEntityIncorporationStateCountryCode_60" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_deiEntityAddressesLineItems" xlink:to="loc_deiEntityIncorporationStateCountryCode_60" xlink:type="arc" order="19" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_EntityAddressAddressLine1" xlink:label="loc_deiEntityAddressAddressLine1_60" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_deiEntityAddressesLineItems" xlink:to="loc_deiEntityAddressAddressLine1_60" xlink:type="arc" order="20" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_EntityAddressAddressLine2" xlink:label="loc_deiEntityAddressAddressLine2_60" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_deiEntityAddressesLineItems" xlink:to="loc_deiEntityAddressAddressLine2_60" xlink:type="arc" order="21" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_EntityAddressAddressLine3" xlink:label="loc_deiEntityAddressAddressLine3_60" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_deiEntityAddressesLineItems" xlink:to="loc_deiEntityAddressAddressLine3_60" xlink:type="arc" order="22" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_EntityAddressCityOrTown" xlink:label="loc_deiEntityAddressCityOrTown_60" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_deiEntityAddressesLineItems" xlink:to="loc_deiEntityAddressCityOrTown_60" xlink:type="arc" order="23" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_EntityAddressStateOrProvince" xlink:label="loc_deiEntityAddressStateOrProvince_60" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_deiEntityAddressesLineItems" xlink:to="loc_deiEntityAddressStateOrProvince_60" xlink:type="arc" order="24" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_EntityAddressCountry" xlink:label="loc_deiEntityAddressCountry_60" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_deiEntityAddressesLineItems" xlink:to="loc_deiEntityAddressCountry_60" xlink:type="arc" order="25" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_EntityAddressPostalZipCode" xlink:label="loc_deiEntityAddressPostalZipCode_60" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_deiEntityAddressesLineItems" xlink:to="loc_deiEntityAddressPostalZipCode_60" xlink:type="arc" order="26" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_CountryRegion" xlink:label="loc_deiCountryRegion_60" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_deiEntityAddressesLineItems" xlink:to="loc_deiCountryRegion_60" xlink:type="arc" order="27" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_CityAreaCode" xlink:label="loc_deiCityAreaCode_60" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_deiEntityAddressesLineItems" xlink:to="loc_deiCityAreaCode_60" xlink:type="arc" order="28" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_LocalPhoneNumber" xlink:label="loc_deiLocalPhoneNumber_60" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_deiEntityAddressesLineItems" xlink:to="loc_deiLocalPhoneNumber_60" xlink:type="arc" order="29" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_Extension" xlink:label="loc_deiExtension_60" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_deiEntityAddressesLineItems" xlink:to="loc_deiExtension_60" xlink:type="arc" order="30" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_WrittenCommunications" xlink:label="loc_deiWrittenCommunications_60" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_deiEntityAddressesLineItems" xlink:to="loc_deiWrittenCommunications_60" xlink:type="arc" order="31" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_SolicitingMaterial" xlink:label="loc_deiSolicitingMaterial_60" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_deiEntityAddressesLineItems" xlink:to="loc_deiSolicitingMaterial_60" xlink:type="arc" order="32" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_PreCommencementTenderOffer" xlink:label="loc_deiPreCommencementTenderOffer_60" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_deiEntityAddressesLineItems" xlink:to="loc_deiPreCommencementTenderOffer_60" xlink:type="arc" order="33" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_PreCommencementIssuerTenderOffer" xlink:label="loc_deiPreCommencementIssuerTenderOffer_60" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_deiEntityAddressesLineItems" xlink:to="loc_deiPreCommencementIssuerTenderOffer_60" xlink:type="arc" order="34" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_Security12bTitle" xlink:label="loc_deiSecurity12bTitle_60" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_deiEntityAddressesLineItems" xlink:to="loc_deiSecurity12bTitle_60" xlink:type="arc" order="35" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_NoTradingSymbolFlag" xlink:label="loc_deiNoTradingSymbolFlag_60" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_deiEntityAddressesLineItems" xlink:to="loc_deiNoTradingSymbolFlag_60" xlink:type="arc" order="36" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_TradingSymbol" xlink:label="loc_deiTradingSymbol_60" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_deiEntityAddressesLineItems" xlink:to="loc_deiTradingSymbol_60" xlink:type="arc" order="37" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_SecurityExchangeName" xlink:label="loc_deiSecurityExchangeName_60" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_deiEntityAddressesLineItems" xlink:to="loc_deiSecurityExchangeName_60" xlink:type="arc" order="38" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_Security12gTitle" xlink:label="loc_deiSecurity12gTitle_60" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_deiEntityAddressesLineItems" xlink:to="loc_deiSecurity12gTitle_60" xlink:type="arc" order="39" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_SecurityReportingObligation" xlink:label="loc_deiSecurityReportingObligation_60" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_deiEntityAddressesLineItems" xlink:to="loc_deiSecurityReportingObligation_60" xlink:type="arc" order="40" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_AnnualInformationForm" xlink:label="loc_deiAnnualInformationForm_60" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_deiEntityAddressesLineItems" xlink:to="loc_deiAnnualInformationForm_60" xlink:type="arc" order="41" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_AuditedAnnualFinancialStatements" xlink:label="loc_deiAuditedAnnualFinancialStatements_60" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_deiEntityAddressesLineItems" xlink:to="loc_deiAuditedAnnualFinancialStatements_60" xlink:type="arc" order="42" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_EntityWellKnownSeasonedIssuer" xlink:label="loc_deiEntityWellKnownSeasonedIssuer_60" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_deiEntityAddressesLineItems" xlink:to="loc_deiEntityWellKnownSeasonedIssuer_60" xlink:type="arc" order="43" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_EntityVoluntaryFilers" xlink:label="loc_deiEntityVoluntaryFilers_60" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_deiEntityAddressesLineItems" xlink:to="loc_deiEntityVoluntaryFilers_60" xlink:type="arc" order="44" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_EntityCurrentReportingStatus" xlink:label="loc_deiEntityCurrentReportingStatus_60" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_deiEntityAddressesLineItems" xlink:to="loc_deiEntityCurrentReportingStatus_60" xlink:type="arc" order="45" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_EntityInteractiveDataCurrent" xlink:label="loc_deiEntityInteractiveDataCurrent_60" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_deiEntityAddressesLineItems" xlink:to="loc_deiEntityInteractiveDataCurrent_60" xlink:type="arc" order="46" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_EntityFilerCategory" xlink:label="loc_deiEntityFilerCategory_60" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_deiEntityAddressesLineItems" xlink:to="loc_deiEntityFilerCategory_60" xlink:type="arc" order="47" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_EntitySmallBusiness" xlink:label="loc_deiEntitySmallBusiness_60" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_deiEntityAddressesLineItems" xlink:to="loc_deiEntitySmallBusiness_60" xlink:type="arc" order="48" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_EntityEmergingGrowthCompany" xlink:label="loc_deiEntityEmergingGrowthCompany_60" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_deiEntityAddressesLineItems" xlink:to="loc_deiEntityEmergingGrowthCompany_60" xlink:type="arc" order="49" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_EntityExTransitionPeriod" xlink:label="loc_deiEntityExTransitionPeriod_60" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_deiEntityAddressesLineItems" xlink:to="loc_deiEntityExTransitionPeriod_60" xlink:type="arc" order="50" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_DocumentAccountingStandard" xlink:label="loc_deiDocumentAccountingStandard_60" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_deiEntityAddressesLineItems" xlink:to="loc_deiDocumentAccountingStandard_60" xlink:type="arc" order="51" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_OtherReportingStandardItemNumber" xlink:label="loc_deiOtherReportingStandardItemNumber_60" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_deiEntityAddressesLineItems" xlink:to="loc_deiOtherReportingStandardItemNumber_60" xlink:type="arc" order="52" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_EntityShellCompany" xlink:label="loc_deiEntityShellCompany_60" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_deiEntityAddressesLineItems" xlink:to="loc_deiEntityShellCompany_60" xlink:type="arc" order="53" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_EntityPublicFloat" xlink:label="loc_deiEntityPublicFloat_60" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_deiEntityAddressesLineItems" xlink:to="loc_deiEntityPublicFloat_60" xlink:type="arc" order="54" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_EntityBankruptcyProceedingsReportingCurrent" xlink:label="loc_deiEntityBankruptcyProceedingsReportingCurrent_60" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_deiEntityAddressesLineItems" xlink:to="loc_deiEntityBankruptcyProceedingsReportingCurrent_60" xlink:type="arc" order="55" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_EntityCommonStockSharesOutstanding" xlink:label="loc_deiEntityCommonStockSharesOutstanding_60" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_deiEntityAddressesLineItems" xlink:to="loc_deiEntityCommonStockSharesOutstanding_60" xlink:type="arc" order="56" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_DocumentsIncorporatedByReferenceTextBlock" xlink:label="loc_deiDocumentsIncorporatedByReferenceTextBlock_60" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_deiEntityAddressesLineItems" xlink:to="loc_deiDocumentsIncorporatedByReferenceTextBlock_60" xlink:type="arc" order="57" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_ContactPersonnelName" xlink:label="loc_deiContactPersonnelName_60" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_deiEntityAddressesLineItems" xlink:to="loc_deiContactPersonnelName_60" xlink:type="arc" order="58" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_ContactPersonnelEmailAddress" xlink:label="loc_deiContactPersonnelEmailAddress_60" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_deiEntityAddressesLineItems" xlink:to="loc_deiContactPersonnelEmailAddress_60" xlink:type="arc" order="59" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_IcfrAuditorAttestationFlag" xlink:label="loc_deiIcfrAuditorAttestationFlag_60" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_deiEntityAddressesLineItems" xlink:to="loc_deiIcfrAuditorAttestationFlag_60" xlink:type="arc" order="60" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_DocumentFinStmtErrorCorrectionFlag" xlink:label="loc_deiDocumentFinStmtErrorCorrectionFlag_60" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_deiEntityAddressesLineItems" xlink:to="loc_deiDocumentFinStmtErrorCorrectionFlag_60" xlink:type="arc" order="61" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_AuditorFirmId" xlink:label="loc_deiAuditorFirmId_60" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_deiEntityAddressesLineItems" xlink:to="loc_deiAuditorFirmId_60" xlink:type="arc" order="62" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_AuditorOpinionTextBlock" xlink:label="loc_deiAuditorOpinionTextBlock_60" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_deiEntityAddressesLineItems" xlink:to="loc_deiAuditorOpinionTextBlock_60" xlink:type="arc" order="63" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_AuditorName" xlink:label="loc_deiAuditorName_60" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_deiEntityAddressesLineItems" xlink:to="loc_deiAuditorName_60" xlink:type="arc" order="64" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_AuditorLocation" xlink:label="loc_deiAuditorLocation_60" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_deiEntityAddressesLineItems" xlink:to="loc_deiAuditorLocation_60" xlink:type="arc" order="65" />
    </link:definitionLink>
    <link:definitionLink xlink:type="extended" xlink:role="http://genenta.com/role/StatementsOfOperationsAndComprehensiveLoss" xlink:title="00000002 - Statement - Consolidated Statements of Operations and Comprehensive Loss" />
    <link:definitionLink xlink:type="extended" xlink:role="http://genenta.com/role/BalanceSheets" xlink:title="00000003 - Statement - Consolidated Balance Sheets">
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanDisclosureLineItems" xlink:label="loc_us-gaapDefinedBenefitPlanDisclosureLineItems" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable" xlink:label="loc_us-gaapScheduleOfDefinedBenefitPlansDisclosuresTable" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xbrldt:contextElement="segment" xlink:from="loc_us-gaapDefinedBenefitPlanDisclosureLineItems" xlink:to="loc_us-gaapScheduleOfDefinedBenefitPlansDisclosuresTable" xlink:type="arc" order="10" xbrldt:closed="true" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RelatedPartyTransactionsByRelatedPartyAxis" xlink:label="loc_us-gaapRelatedPartyTransactionsByRelatedPartyAxis" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaapScheduleOfDefinedBenefitPlansDisclosuresTable" xlink:to="loc_us-gaapRelatedPartyTransactionsByRelatedPartyAxis" xlink:type="arc" order="1" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RelatedPartyDomain" xlink:label="loc_us-gaapRelatedPartyDomain" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaapRelatedPartyTransactionsByRelatedPartyAxis" xlink:to="loc_us-gaapRelatedPartyDomain" xlink:type="arc" order="20" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RelatedPartyDomain" xlink:label="loc_us-gaapRelatedPartyDomain_10" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xbrldt:contextElement="segment" xlink:from="loc_us-gaapRelatedPartyTransactionsByRelatedPartyAxis" xlink:to="loc_us-gaapRelatedPartyDomain_10" xlink:type="arc" order="30" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_NonrelatedPartyMember" xlink:label="loc_us-gaapNonrelatedPartyMember_30" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapRelatedPartyDomain" xlink:to="loc_us-gaapNonrelatedPartyMember_30" xlink:type="arc" order="31" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RelatedPartyMember" xlink:label="loc_us-gaapRelatedPartyMember_60" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapRelatedPartyDomain" xlink:to="loc_us-gaapRelatedPartyMember_60" xlink:type="arc" order="61" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AssetsAbstract" xlink:label="loc_us-gaapAssetsAbstract_100" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapDefinedBenefitPlanDisclosureLineItems" xlink:to="loc_us-gaapAssetsAbstract_100" xlink:type="arc" order="0" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AssetsCurrentAbstract" xlink:label="loc_us-gaapAssetsCurrentAbstract_100" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapAssetsAbstract_100" xlink:to="loc_us-gaapAssetsCurrentAbstract_100" xlink:type="arc" order="1" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CashAndCashEquivalentsAtCarryingValue" xlink:label="loc_us-gaapCashAndCashEquivalentsAtCarryingValue_100" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapAssetsCurrentAbstract_100" xlink:to="loc_us-gaapCashAndCashEquivalentsAtCarryingValue_100" xlink:type="arc" order="2" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_MarketableSecuritiesCurrent" xlink:label="loc_us-gaapMarketableSecuritiesCurrent_100" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapAssetsCurrentAbstract_100" xlink:to="loc_us-gaapMarketableSecuritiesCurrent_100" xlink:type="arc" order="3" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PrepaidExpenseAndOtherAssetsCurrent" xlink:label="loc_us-gaapPrepaidExpenseAndOtherAssetsCurrent_100" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapAssetsCurrentAbstract_100" xlink:to="loc_us-gaapPrepaidExpenseAndOtherAssetsCurrent_100" xlink:type="arc" order="4" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AssetsCurrent" xlink:label="loc_us-gaapAssetsCurrent_100" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapAssetsCurrentAbstract_100" xlink:to="loc_us-gaapAssetsCurrent_100" xlink:type="arc" order="5" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AssetsNoncurrentAbstract" xlink:label="loc_us-gaapAssetsNoncurrentAbstract_100" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapAssetsAbstract_100" xlink:to="loc_us-gaapAssetsNoncurrentAbstract_100" xlink:type="arc" order="6" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PropertyPlantAndEquipmentNet" xlink:label="loc_us-gaapPropertyPlantAndEquipmentNet_100" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapAssetsNoncurrentAbstract_100" xlink:to="loc_us-gaapPropertyPlantAndEquipmentNet_100" xlink:type="arc" order="7" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_OtherAssetsNoncurrent" xlink:label="loc_us-gaapOtherAssetsNoncurrent_100" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapAssetsNoncurrentAbstract_100" xlink:to="loc_us-gaapOtherAssetsNoncurrent_100" xlink:type="arc" order="8" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AssetsNoncurrent" xlink:label="loc_us-gaapAssetsNoncurrent_100" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapAssetsNoncurrentAbstract_100" xlink:to="loc_us-gaapAssetsNoncurrent_100" xlink:type="arc" order="9" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_Assets" xlink:label="loc_us-gaapAssets_100" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapAssetsAbstract_100" xlink:to="loc_us-gaapAssets_100" xlink:type="arc" order="10" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LiabilitiesAndStockholdersEquityAbstract" xlink:label="loc_us-gaapLiabilitiesAndStockholdersEquityAbstract_100" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapDefinedBenefitPlanDisclosureLineItems" xlink:to="loc_us-gaapLiabilitiesAndStockholdersEquityAbstract_100" xlink:type="arc" order="11" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LiabilitiesCurrentAbstract" xlink:label="loc_us-gaapLiabilitiesCurrentAbstract_100" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapLiabilitiesAndStockholdersEquityAbstract_100" xlink:to="loc_us-gaapLiabilitiesCurrentAbstract_100" xlink:type="arc" order="12" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AccountsPayableCurrent" xlink:label="loc_us-gaapAccountsPayableCurrent_100" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapLiabilitiesCurrentAbstract_100" xlink:to="loc_us-gaapAccountsPayableCurrent_100" xlink:type="arc" order="13" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AccruedLiabilitiesCurrent" xlink:label="loc_us-gaapAccruedLiabilitiesCurrent_100" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapLiabilitiesCurrentAbstract_100" xlink:to="loc_us-gaapAccruedLiabilitiesCurrent_100" xlink:type="arc" order="14" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_OtherLiabilitiesCurrent" xlink:label="loc_us-gaapOtherLiabilitiesCurrent_100" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapLiabilitiesCurrentAbstract_100" xlink:to="loc_us-gaapOtherLiabilitiesCurrent_100" xlink:type="arc" order="15" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LiabilitiesCurrent" xlink:label="loc_us-gaapLiabilitiesCurrent_100" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapLiabilitiesCurrentAbstract_100" xlink:to="loc_us-gaapLiabilitiesCurrent_100" xlink:type="arc" order="16" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LiabilitiesNoncurrentAbstract" xlink:label="loc_us-gaapLiabilitiesNoncurrentAbstract_100" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapLiabilitiesAndStockholdersEquityAbstract_100" xlink:to="loc_us-gaapLiabilitiesNoncurrentAbstract_100" xlink:type="arc" order="17" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_OtherLiabilitiesNoncurrent" xlink:label="loc_us-gaapOtherLiabilitiesNoncurrent_100" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapLiabilitiesAndStockholdersEquityAbstract_100" xlink:to="loc_us-gaapOtherLiabilitiesNoncurrent_100" xlink:type="arc" order="18" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent" xlink:label="loc_us-gaapPensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent_100" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapLiabilitiesAndStockholdersEquityAbstract_100" xlink:to="loc_us-gaapPensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent_100" xlink:type="arc" order="19" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LiabilitiesNoncurrent" xlink:label="loc_us-gaapLiabilitiesNoncurrent_100" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapLiabilitiesAndStockholdersEquityAbstract_100" xlink:to="loc_us-gaapLiabilitiesNoncurrent_100" xlink:type="arc" order="20" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CommitmentsAndContingencies" xlink:label="loc_us-gaapCommitmentsAndContingencies_100" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapLiabilitiesAndStockholdersEquityAbstract_100" xlink:to="loc_us-gaapCommitmentsAndContingencies_100" xlink:type="arc" order="21" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StockholdersEquityAbstract" xlink:label="loc_us-gaapStockholdersEquityAbstract_100" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapLiabilitiesAndStockholdersEquityAbstract_100" xlink:to="loc_us-gaapStockholdersEquityAbstract_100" xlink:type="arc" order="22" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CommonStockValue" xlink:label="loc_us-gaapCommonStockValue_100" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapStockholdersEquityAbstract_100" xlink:to="loc_us-gaapCommonStockValue_100" xlink:type="arc" order="23" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RetainedEarningsAccumulatedDeficit" xlink:label="loc_us-gaapRetainedEarningsAccumulatedDeficit_100" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapStockholdersEquityAbstract_100" xlink:to="loc_us-gaapRetainedEarningsAccumulatedDeficit_100" xlink:type="arc" order="24" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax" xlink:label="loc_us-gaapAccumulatedOtherComprehensiveIncomeLossNetOfTax_100" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapStockholdersEquityAbstract_100" xlink:to="loc_us-gaapAccumulatedOtherComprehensiveIncomeLossNetOfTax_100" xlink:type="arc" order="25" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StockholdersEquity" xlink:label="loc_us-gaapStockholdersEquity_100" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapStockholdersEquityAbstract_100" xlink:to="loc_us-gaapStockholdersEquity_100" xlink:type="arc" order="26" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LiabilitiesAndStockholdersEquity" xlink:label="loc_us-gaapLiabilitiesAndStockholdersEquity_100" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapLiabilitiesAndStockholdersEquityAbstract_100" xlink:to="loc_us-gaapLiabilitiesAndStockholdersEquity_100" xlink:type="arc" order="27" />
    </link:definitionLink>
    <link:definitionLink xlink:type="extended" xlink:role="http://genenta.com/role/BalanceSheetsParenthetical" xlink:title="00000004 - Statement - Consolidated Balance Sheets (Parenthetical)" />
    <link:definitionLink xlink:type="extended" xlink:role="http://genenta.com/role/StatementOfChangesInShareholdersEquity" xlink:title="00000005 - Statement - Consolidated Statement of Changes in Shareholders&apos; Equity">
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StatementLineItems" xlink:label="loc_us-gaapStatementLineItems" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StatementTable" xlink:label="loc_us-gaapStatementTable" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xbrldt:contextElement="segment" xlink:from="loc_us-gaapStatementLineItems" xlink:to="loc_us-gaapStatementTable" xlink:type="arc" order="10" xbrldt:closed="true" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StatementEquityComponentsAxis" xlink:label="loc_us-gaapStatementEquityComponentsAxis" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaapStatementTable" xlink:to="loc_us-gaapStatementEquityComponentsAxis" xlink:type="arc" order="1" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_EquityComponentDomain" xlink:label="loc_us-gaapEquityComponentDomain" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaapStatementEquityComponentsAxis" xlink:to="loc_us-gaapEquityComponentDomain" xlink:type="arc" order="20" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_EquityComponentDomain" xlink:label="loc_us-gaapEquityComponentDomain_10" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xbrldt:contextElement="segment" xlink:from="loc_us-gaapStatementEquityComponentsAxis" xlink:to="loc_us-gaapEquityComponentDomain_10" xlink:type="arc" order="30" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CommonStockMember" xlink:label="loc_us-gaapCommonStockMember_0" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapEquityComponentDomain" xlink:to="loc_us-gaapCommonStockMember_0" xlink:type="arc" order="1" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RetainedEarningsMember" xlink:label="loc_us-gaapRetainedEarningsMember_10" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapEquityComponentDomain" xlink:to="loc_us-gaapRetainedEarningsMember_10" xlink:type="arc" order="11" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeMember" xlink:label="loc_us-gaapAccumulatedOtherComprehensiveIncomeMember_20" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapEquityComponentDomain" xlink:to="loc_us-gaapAccumulatedOtherComprehensiveIncomeMember_20" xlink:type="arc" order="21" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StockholdersEquity" xlink:label="loc_us-gaapStockholdersEquity_50" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapStatementLineItems" xlink:to="loc_us-gaapStockholdersEquity_50" xlink:type="arc" order="1" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SharesOutstanding" xlink:label="loc_us-gaapSharesOutstanding_50" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapStatementLineItems" xlink:to="loc_us-gaapSharesOutstanding_50" xlink:type="arc" order="2" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StockIssuedDuringPeriodValueShareBasedCompensation" xlink:label="loc_us-gaapStockIssuedDuringPeriodValueShareBasedCompensation_50" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapStatementLineItems" xlink:to="loc_us-gaapStockIssuedDuringPeriodValueShareBasedCompensation_50" xlink:type="arc" order="3" />
      <link:loc xlink:type="locator" xlink:href="gnta-20241231.xsd#GNTA_CumulativeTranslationAdjustment" xlink:label="loc_GNTACumulativeTranslationAdjustment_50" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapStatementLineItems" xlink:to="loc_GNTACumulativeTranslationAdjustment_50" xlink:type="arc" order="4" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_NetIncomeLoss" xlink:label="loc_us-gaapNetIncomeLoss_50" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapStatementLineItems" xlink:to="loc_us-gaapNetIncomeLoss_50" xlink:type="arc" order="5" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StockIssuedDuringPeriodValueNewIssues" xlink:label="loc_us-gaapStockIssuedDuringPeriodValueNewIssues_50" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapStatementLineItems" xlink:to="loc_us-gaapStockIssuedDuringPeriodValueNewIssues_50" xlink:type="arc" order="6" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StockIssuedDuringPeriodSharesNewIssues" xlink:label="loc_us-gaapStockIssuedDuringPeriodSharesNewIssues_50" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapStatementLineItems" xlink:to="loc_us-gaapStockIssuedDuringPeriodSharesNewIssues_50" xlink:type="arc" order="7" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_OtherComprehensiveIncomeLossNetOfTax" xlink:label="loc_us-gaapOtherComprehensiveIncomeLossNetOfTax_50" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapStatementLineItems" xlink:to="loc_us-gaapOtherComprehensiveIncomeLossNetOfTax_50" xlink:type="arc" order="8" />
    </link:definitionLink>
    <link:definitionLink xlink:type="extended" xlink:role="http://genenta.com/role/StatementsOfCashFlows" xlink:title="00000006 - Statement - Consolidated Statements of Cash Flows" />
    <link:definitionLink xlink:type="extended" xlink:role="http://xbrl.sec.gov/cyd/role/CybersecurityRiskManagementAndStrategyDisclosure" xlink:title="00000012 - Disclosure - Cybersecurity Risk Management and Strategy Disclosure" />
    <link:definitionLink xlink:type="extended" xlink:role="http://xbrl.sec.gov/cyd/role/MaterialCybersecurityIncidentDisclosure" xlink:title="00000013 - Disclosure - Material Cybersecurity Incident Disclosure" />
    <link:definitionLink xlink:type="extended" xlink:role="http://genenta.com/role/NatureOfBusinessAndHistory" xlink:title="999014 - Disclosure - Nature of business and history" />
    <link:definitionLink xlink:type="extended" xlink:role="http://genenta.com/role/SummaryOfSignificantAccountingPolicies" xlink:title="999015 - Disclosure - Summary of significant accounting policies" />
    <link:definitionLink xlink:type="extended" xlink:role="http://genenta.com/role/ResearchAndDevelopment" xlink:title="999016 - Disclosure - Research and development" />
    <link:definitionLink xlink:type="extended" xlink:role="http://genenta.com/role/GeneralAndAdministrative" xlink:title="999017 - Disclosure - General and administrative" />
    <link:definitionLink xlink:type="extended" xlink:role="http://genenta.com/role/IncomeTaxes" xlink:title="999018 - Disclosure - Income taxes" />
    <link:definitionLink xlink:type="extended" xlink:role="http://genenta.com/role/PrepaidExpensesAndOtherCurrentAssets" xlink:title="999019 - Disclosure - Prepaid expenses and other current assets" />
    <link:definitionLink xlink:type="extended" xlink:role="http://genenta.com/role/FixedAssetsNet" xlink:title="999020 - Disclosure - Fixed assets, net" />
    <link:definitionLink xlink:type="extended" xlink:role="http://genenta.com/role/Non-currentAssetsRightOfUseRou" xlink:title="999021 - Disclosure - Non-current assets right of use (ROU)" />
    <link:definitionLink xlink:type="extended" xlink:role="http://genenta.com/role/OtherNon-currentAssets" xlink:title="999022 - Disclosure - Other non-current assets" />
    <link:definitionLink xlink:type="extended" xlink:role="http://genenta.com/role/RetirementBenefitObligation" xlink:title="999023 - Disclosure - Retirement benefit obligation" />
    <link:definitionLink xlink:type="extended" xlink:role="http://genenta.com/role/ShareholdersEquity" xlink:title="999024 - Disclosure - Shareholders&#8217; equity" />
    <link:definitionLink xlink:type="extended" xlink:role="http://genenta.com/role/Share-basedCompensation" xlink:title="999025 - Disclosure - Share-based compensation" />
    <link:definitionLink xlink:type="extended" xlink:role="http://genenta.com/role/AccumulatedOtherComprehensiveIncome" xlink:title="999026 - Disclosure - Accumulated other comprehensive income" />
    <link:definitionLink xlink:type="extended" xlink:role="http://genenta.com/role/RelatedParties" xlink:title="999027 - Disclosure - Related parties" />
    <link:definitionLink xlink:type="extended" xlink:role="http://genenta.com/role/CommitmentsAndContingencies" xlink:title="999028 - Disclosure - Commitments and contingencies" />
    <link:definitionLink xlink:type="extended" xlink:role="http://genenta.com/role/SubsequentEvents" xlink:title="999029 - Disclosure - Subsequent events" />
    <link:definitionLink xlink:type="extended" xlink:role="http://genenta.com/role/SummaryOfSignificantAccountingPoliciesPolicies" xlink:title="999030 - Disclosure - Summary of significant accounting policies (Policies)" />
    <link:definitionLink xlink:type="extended" xlink:role="http://genenta.com/role/SummaryOfSignificantAccountingPoliciesTables" xlink:title="999031 - Disclosure - Summary of significant accounting policies (Tables)" />
    <link:definitionLink xlink:type="extended" xlink:role="http://genenta.com/role/IncomeTaxesTables" xlink:title="999032 - Disclosure - Income taxes (Tables)" />
    <link:definitionLink xlink:type="extended" xlink:role="http://genenta.com/role/PrepaidExpensesAndOtherCurrentAssetsTables" xlink:title="999033 - Disclosure - Prepaid expenses and other current assets (Tables)" />
    <link:definitionLink xlink:type="extended" xlink:role="http://genenta.com/role/FixedAssetsNetTables" xlink:title="999034 - Disclosure - Fixed assets, net (Tables)" />
    <link:definitionLink xlink:type="extended" xlink:role="http://genenta.com/role/OtherNon-currentAssetsTables" xlink:title="999035 - Disclosure - Other non-current assets (Tables)" />
    <link:definitionLink xlink:type="extended" xlink:role="http://genenta.com/role/Share-basedCompensationTables" xlink:title="999036 - Disclosure - Share-based compensation (Tables)" />
    <link:definitionLink xlink:type="extended" xlink:role="http://genenta.com/role/AccumulatedOtherComprehensiveIncomeTables" xlink:title="999037 - Disclosure - Accumulated other comprehensive income (Tables)" />
    <link:definitionLink xlink:type="extended" xlink:role="http://genenta.com/role/RelatedPartiesTables" xlink:title="999038 - Disclosure - Related parties (Tables)">
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StatementLineItems" xlink:label="loc_us-gaapStatementLineItems" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StatementTable" xlink:label="loc_us-gaapStatementTable" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xbrldt:contextElement="segment" xlink:from="loc_us-gaapStatementLineItems" xlink:to="loc_us-gaapStatementTable" xlink:type="arc" order="10" xbrldt:closed="true" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_IncomeStatementLocationAxis" xlink:label="loc_us-gaapIncomeStatementLocationAxis" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaapStatementTable" xlink:to="loc_us-gaapIncomeStatementLocationAxis" xlink:type="arc" order="1" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_IncomeStatementLocationDomain" xlink:label="loc_us-gaapIncomeStatementLocationDomain" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaapIncomeStatementLocationAxis" xlink:to="loc_us-gaapIncomeStatementLocationDomain" xlink:type="arc" order="20" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_IncomeStatementLocationDomain" xlink:label="loc_us-gaapIncomeStatementLocationDomain_10" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xbrldt:contextElement="segment" xlink:from="loc_us-gaapIncomeStatementLocationAxis" xlink:to="loc_us-gaapIncomeStatementLocationDomain_10" xlink:type="arc" order="30" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ResearchAndDevelopmentExpenseMember" xlink:label="loc_us-gaapResearchAndDevelopmentExpenseMember_10" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapIncomeStatementLocationDomain" xlink:to="loc_us-gaapResearchAndDevelopmentExpenseMember_10" xlink:type="arc" order="11" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_GeneralAndAdministrativeExpenseMember" xlink:label="loc_us-gaapGeneralAndAdministrativeExpenseMember_20" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapIncomeStatementLocationDomain" xlink:to="loc_us-gaapGeneralAndAdministrativeExpenseMember_20" xlink:type="arc" order="21" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfRelatedPartyTransactionsTableTextBlock" xlink:label="loc_us-gaapScheduleOfRelatedPartyTransactionsTableTextBlock_40" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapStatementLineItems" xlink:to="loc_us-gaapScheduleOfRelatedPartyTransactionsTableTextBlock_40" xlink:type="arc" order="0" />
      <link:loc xlink:type="locator" xlink:href="gnta-20241231.xsd#GNTA_ScheduleOfAccountsPayableToRelatedPartiesTableTextBlock" xlink:label="loc_GNTAScheduleOfAccountsPayableToRelatedPartiesTableTextBlock_40" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapStatementLineItems" xlink:to="loc_GNTAScheduleOfAccountsPayableToRelatedPartiesTableTextBlock_40" xlink:type="arc" order="1" />
      <link:loc xlink:type="locator" xlink:href="gnta-20241231.xsd#GNTA_ScheduleOfAccruedExpenseToRelatedPartiesTableTextBlock" xlink:label="loc_GNTAScheduleOfAccruedExpenseToRelatedPartiesTableTextBlock_40" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapStatementLineItems" xlink:to="loc_GNTAScheduleOfAccruedExpenseToRelatedPartiesTableTextBlock_40" xlink:type="arc" order="2" />
    </link:definitionLink>
    <link:definitionLink xlink:type="extended" xlink:role="http://genenta.com/role/CommitmentsAndContingenciesTables" xlink:title="999039 - Disclosure - Commitments and contingencies (Tables)" />
    <link:definitionLink xlink:type="extended" xlink:role="http://genenta.com/role/NatureOfBusinessAndHistoryDetailsNarrative" xlink:title="999040 - Disclosure - Nature of business and history (Details Narrative)">
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CollaborativeArrangementsAndNoncollaborativeArrangementTransactionsLineItems" xlink:label="loc_us-gaapCollaborativeArrangementsAndNoncollaborativeArrangementTransactionsLineItems" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfCollaborativeArrangementsAndNoncollaborativeArrangementTransactionsTable" xlink:label="loc_us-gaapScheduleOfCollaborativeArrangementsAndNoncollaborativeArrangementTransactionsTable" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xbrldt:contextElement="segment" xlink:from="loc_us-gaapCollaborativeArrangementsAndNoncollaborativeArrangementTransactionsLineItems" xlink:to="loc_us-gaapScheduleOfCollaborativeArrangementsAndNoncollaborativeArrangementTransactionsTable" xlink:type="arc" order="10" xbrldt:closed="true" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_TypeOfArrangementAxis" xlink:label="loc_us-gaapTypeOfArrangementAxis" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaapScheduleOfCollaborativeArrangementsAndNoncollaborativeArrangementTransactionsTable" xlink:to="loc_us-gaapTypeOfArrangementAxis" xlink:type="arc" order="1" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ArrangementsAndNonarrangementTransactionsMember" xlink:label="loc_us-gaapArrangementsAndNonarrangementTransactionsMember" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaapTypeOfArrangementAxis" xlink:to="loc_us-gaapArrangementsAndNonarrangementTransactionsMember" xlink:type="arc" order="20" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ArrangementsAndNonarrangementTransactionsMember" xlink:label="loc_us-gaapArrangementsAndNonarrangementTransactionsMember_10" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xbrldt:contextElement="segment" xlink:from="loc_us-gaapTypeOfArrangementAxis" xlink:to="loc_us-gaapArrangementsAndNonarrangementTransactionsMember_10" xlink:type="arc" order="30" />
      <link:loc xlink:type="locator" xlink:href="gnta-20241231.xsd#GNTA_ShelfRegistrationStatementMember" xlink:label="loc_GNTAShelfRegistrationStatementMember_40" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapArrangementsAndNonarrangementTransactionsMember" xlink:to="loc_GNTAShelfRegistrationStatementMember_40" xlink:type="arc" order="41" />
      <link:loc xlink:type="locator" xlink:href="gnta-20241231.xsd#GNTA_SalesAgreementMember" xlink:label="loc_GNTASalesAgreementMember_60" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapArrangementsAndNonarrangementTransactionsMember" xlink:to="loc_GNTASalesAgreementMember_60" xlink:type="arc" order="61" />
      <link:loc xlink:type="locator" xlink:href="gnta-20241231.xsd#GNTA_CurrentSalesAgreementMember" xlink:label="loc_GNTACurrentSalesAgreementMember_110" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapArrangementsAndNonarrangementTransactionsMember" xlink:to="loc_GNTACurrentSalesAgreementMember_110" xlink:type="arc" order="111" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StatementEquityComponentsAxis" xlink:label="loc_us-gaapStatementEquityComponentsAxis" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaapScheduleOfCollaborativeArrangementsAndNoncollaborativeArrangementTransactionsTable" xlink:to="loc_us-gaapStatementEquityComponentsAxis" xlink:type="arc" order="2" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_EquityComponentDomain" xlink:label="loc_us-gaapEquityComponentDomain" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaapStatementEquityComponentsAxis" xlink:to="loc_us-gaapEquityComponentDomain" xlink:type="arc" order="20" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_EquityComponentDomain" xlink:label="loc_us-gaapEquityComponentDomain_10" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xbrldt:contextElement="segment" xlink:from="loc_us-gaapStatementEquityComponentsAxis" xlink:to="loc_us-gaapEquityComponentDomain_10" xlink:type="arc" order="30" />
      <link:loc xlink:type="locator" xlink:href="gnta-20241231.xsd#GNTA_AmericanDepositorySharesMember" xlink:label="loc_GNTAAmericanDepositorySharesMember_50" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapEquityComponentDomain" xlink:to="loc_GNTAAmericanDepositorySharesMember_50" xlink:type="arc" order="51" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_RangeAxis" xlink:label="loc_srtRangeAxis" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaapScheduleOfCollaborativeArrangementsAndNoncollaborativeArrangementTransactionsTable" xlink:to="loc_srtRangeAxis" xlink:type="arc" order="3" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_RangeMember" xlink:label="loc_srtRangeMember" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srtRangeAxis" xlink:to="loc_srtRangeMember" xlink:type="arc" order="20" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_RangeMember" xlink:label="loc_srtRangeMember_10" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xbrldt:contextElement="segment" xlink:from="loc_srtRangeAxis" xlink:to="loc_srtRangeMember_10" xlink:type="arc" order="30" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_MaximumMember" xlink:label="loc_srtMaximumMember_120" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srtRangeMember" xlink:to="loc_srtMaximumMember_120" xlink:type="arc" order="122" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_NetIncomeLoss" xlink:label="loc_us-gaapNetIncomeLoss_150" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapCollaborativeArrangementsAndNoncollaborativeArrangementTransactionsLineItems" xlink:to="loc_us-gaapNetIncomeLoss_150" xlink:type="arc" order="0" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RetainedEarningsAccumulatedDeficit" xlink:label="loc_us-gaapRetainedEarningsAccumulatedDeficit_150" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapCollaborativeArrangementsAndNoncollaborativeArrangementTransactionsLineItems" xlink:to="loc_us-gaapRetainedEarningsAccumulatedDeficit_150" xlink:type="arc" order="1" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CashCashEquivalentsAndShortTermInvestments" xlink:label="loc_us-gaapCashCashEquivalentsAndShortTermInvestments_150" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapCollaborativeArrangementsAndNoncollaborativeArrangementTransactionsLineItems" xlink:to="loc_us-gaapCashCashEquivalentsAndShortTermInvestments_150" xlink:type="arc" order="2" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ProceedsFromIssuanceOrSaleOfEquity" xlink:label="loc_us-gaapProceedsFromIssuanceOrSaleOfEquity_150" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapCollaborativeArrangementsAndNoncollaborativeArrangementTransactionsLineItems" xlink:to="loc_us-gaapProceedsFromIssuanceOrSaleOfEquity_150" xlink:type="arc" order="3" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SharesIssued" xlink:label="loc_us-gaapSharesIssued_150" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapCollaborativeArrangementsAndNoncollaborativeArrangementTransactionsLineItems" xlink:to="loc_us-gaapSharesIssued_150" xlink:type="arc" order="4" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SharesOutstanding" xlink:label="loc_us-gaapSharesOutstanding_150" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapCollaborativeArrangementsAndNoncollaborativeArrangementTransactionsLineItems" xlink:to="loc_us-gaapSharesOutstanding_150" xlink:type="arc" order="5" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StockIssuedDuringPeriodValueNewIssues" xlink:label="loc_us-gaapStockIssuedDuringPeriodValueNewIssues_150" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapCollaborativeArrangementsAndNoncollaborativeArrangementTransactionsLineItems" xlink:to="loc_us-gaapStockIssuedDuringPeriodValueNewIssues_150" xlink:type="arc" order="6" />
      <link:loc xlink:type="locator" xlink:href="gnta-20241231.xsd#GNTA_SaleOfStockAggregateOfferingPrice" xlink:label="loc_GNTASaleOfStockAggregateOfferingPrice_150" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapCollaborativeArrangementsAndNoncollaborativeArrangementTransactionsLineItems" xlink:to="loc_GNTASaleOfStockAggregateOfferingPrice_150" xlink:type="arc" order="7" />
      <link:loc xlink:type="locator" xlink:href="gnta-20241231.xsd#GNTA_SaleOfStockValueOfShareAvailableToBeSold" xlink:label="loc_GNTASaleOfStockValueOfShareAvailableToBeSold_150" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapCollaborativeArrangementsAndNoncollaborativeArrangementTransactionsLineItems" xlink:to="loc_GNTASaleOfStockValueOfShareAvailableToBeSold_150" xlink:type="arc" order="8" />
      <link:loc xlink:type="locator" xlink:href="gnta-20241231.xsd#GNTA_SaleOfStockRemainingValueOfShare" xlink:label="loc_GNTASaleOfStockRemainingValueOfShare_150" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapCollaborativeArrangementsAndNoncollaborativeArrangementTransactionsLineItems" xlink:to="loc_GNTASaleOfStockRemainingValueOfShare_150" xlink:type="arc" order="9" />
      <link:loc xlink:type="locator" xlink:href="gnta-20241231.xsd#GNTA_SaleOfStockAdditionalValueOfShare" xlink:label="loc_GNTASaleOfStockAdditionalValueOfShare_150" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapCollaborativeArrangementsAndNoncollaborativeArrangementTransactionsLineItems" xlink:to="loc_GNTASaleOfStockAdditionalValueOfShare_150" xlink:type="arc" order="10" />
      <link:loc xlink:type="locator" xlink:href="gnta-20241231.xsd#GNTA_SaleOfStockCommissionPercentage" xlink:label="loc_GNTASaleOfStockCommissionPercentage_150" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapCollaborativeArrangementsAndNoncollaborativeArrangementTransactionsLineItems" xlink:to="loc_GNTASaleOfStockCommissionPercentage_150" xlink:type="arc" order="11" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CashAndCashEquivalentsAtCarryingValue" xlink:label="loc_us-gaapCashAndCashEquivalentsAtCarryingValue_150" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapCollaborativeArrangementsAndNoncollaborativeArrangementTransactionsLineItems" xlink:to="loc_us-gaapCashAndCashEquivalentsAtCarryingValue_150" xlink:type="arc" order="12" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_MarketableSecurities" xlink:label="loc_us-gaapMarketableSecurities_150" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapCollaborativeArrangementsAndNoncollaborativeArrangementTransactionsLineItems" xlink:to="loc_us-gaapMarketableSecurities_150" xlink:type="arc" order="13" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ForeignCurrencyTransactionLossBeforeTax" xlink:label="loc_us-gaapForeignCurrencyTransactionLossBeforeTax_150" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapCollaborativeArrangementsAndNoncollaborativeArrangementTransactionsLineItems" xlink:to="loc_us-gaapForeignCurrencyTransactionLossBeforeTax_150" xlink:type="arc" order="14" />
    </link:definitionLink>
    <link:definitionLink xlink:type="extended" xlink:role="http://genenta.com/role/ScheduleOfCashAndCashEquivalentsDetails" xlink:title="999041 - Disclosure - Schedule of cash and cash equivalents (Details)" />
    <link:definitionLink xlink:type="extended" xlink:role="http://genenta.com/role/ScheduleOfMarketableSecuritiesDetails" xlink:title="999042 - Disclosure - Schedule of Marketable securities (Details)">
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtSecuritiesHeldtomaturityAllowanceForCreditLossLineItems" xlink:label="loc_us-gaapDebtSecuritiesHeldtomaturityAllowanceForCreditLossLineItems" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtSecuritiesHeldToMaturityAllowanceForCreditLossTable" xlink:label="loc_us-gaapDebtSecuritiesHeldToMaturityAllowanceForCreditLossTable" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xbrldt:contextElement="segment" xlink:from="loc_us-gaapDebtSecuritiesHeldtomaturityAllowanceForCreditLossLineItems" xlink:to="loc_us-gaapDebtSecuritiesHeldToMaturityAllowanceForCreditLossTable" xlink:type="arc" order="10" xbrldt:closed="true" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FinancialInstrumentAxis" xlink:label="loc_us-gaapFinancialInstrumentAxis" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaapDebtSecuritiesHeldToMaturityAllowanceForCreditLossTable" xlink:to="loc_us-gaapFinancialInstrumentAxis" xlink:type="arc" order="1" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain" xlink:label="loc_us-gaapTransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaapFinancialInstrumentAxis" xlink:to="loc_us-gaapTransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain" xlink:type="arc" order="20" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain" xlink:label="loc_us-gaapTransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_10" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xbrldt:contextElement="segment" xlink:from="loc_us-gaapFinancialInstrumentAxis" xlink:to="loc_us-gaapTransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_10" xlink:type="arc" order="30" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AvailableforsaleSecuritiesMember" xlink:label="loc_us-gaapAvailableforsaleSecuritiesMember_0" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapTransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain" xlink:to="loc_us-gaapAvailableforsaleSecuritiesMember_0" xlink:type="arc" order="1" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtSecuritiesAvailableForSaleAmortizedCostExcludingAccruedInterestAfterAllowanceForCreditLoss" xlink:label="loc_us-gaapDebtSecuritiesAvailableForSaleAmortizedCostExcludingAccruedInterestAfterAllowanceForCreditLoss_50" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapDebtSecuritiesHeldtomaturityAllowanceForCreditLossLineItems" xlink:to="loc_us-gaapDebtSecuritiesAvailableForSaleAmortizedCostExcludingAccruedInterestAfterAllowanceForCreditLoss_50" xlink:type="arc" order="0" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtSecuritiesAvailableForSaleExcludingAccruedInterest" xlink:label="loc_us-gaapDebtSecuritiesAvailableForSaleExcludingAccruedInterest_50" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapDebtSecuritiesHeldtomaturityAllowanceForCreditLossLineItems" xlink:to="loc_us-gaapDebtSecuritiesAvailableForSaleExcludingAccruedInterest_50" xlink:type="arc" order="1" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtSecuritiesAvailableForSaleAccumulatedGrossUnrealizedGainLossBeforeTax" xlink:label="loc_us-gaapDebtSecuritiesAvailableForSaleAccumulatedGrossUnrealizedGainLossBeforeTax_50" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapDebtSecuritiesHeldtomaturityAllowanceForCreditLossLineItems" xlink:to="loc_us-gaapDebtSecuritiesAvailableForSaleAccumulatedGrossUnrealizedGainLossBeforeTax_50" xlink:type="arc" order="2" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtSecuritiesAvailableForSaleAllowanceForCreditLoss" xlink:label="loc_us-gaapDebtSecuritiesAvailableForSaleAllowanceForCreditLoss_50" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapDebtSecuritiesHeldtomaturityAllowanceForCreditLossLineItems" xlink:to="loc_us-gaapDebtSecuritiesAvailableForSaleAllowanceForCreditLoss_50" xlink:type="arc" order="3" />
    </link:definitionLink>
    <link:definitionLink xlink:type="extended" xlink:role="http://genenta.com/role/ScheduleOfFairValuesDueToShort-termNatureOfAssetsAndLiabilitiesDetails" xlink:title="999043 - Disclosure - Schedule of fair values due to short-term nature of assets and liabilities (Details)">
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_PlatformOperatorCryptoAssetLineItems" xlink:label="loc_srtPlatformOperatorCryptoAssetLineItems" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_PlatformOperatorCryptoAssetTable" xlink:label="loc_srtPlatformOperatorCryptoAssetTable" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xbrldt:contextElement="segment" xlink:from="loc_srtPlatformOperatorCryptoAssetLineItems" xlink:to="loc_srtPlatformOperatorCryptoAssetTable" xlink:type="arc" order="10" xbrldt:closed="true" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueByFairValueHierarchyLevelAxis" xlink:label="loc_us-gaapFairValueByFairValueHierarchyLevelAxis" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_srtPlatformOperatorCryptoAssetTable" xlink:to="loc_us-gaapFairValueByFairValueHierarchyLevelAxis" xlink:type="arc" order="1" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain" xlink:label="loc_us-gaapFairValueMeasurementsFairValueHierarchyDomain" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaapFairValueByFairValueHierarchyLevelAxis" xlink:to="loc_us-gaapFairValueMeasurementsFairValueHierarchyDomain" xlink:type="arc" order="20" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain" xlink:label="loc_us-gaapFairValueMeasurementsFairValueHierarchyDomain_10" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xbrldt:contextElement="segment" xlink:from="loc_us-gaapFairValueByFairValueHierarchyLevelAxis" xlink:to="loc_us-gaapFairValueMeasurementsFairValueHierarchyDomain_10" xlink:type="arc" order="30" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueInputsLevel1Member" xlink:label="loc_us-gaapFairValueInputsLevel1Member_10" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapFairValueMeasurementsFairValueHierarchyDomain" xlink:to="loc_us-gaapFairValueInputsLevel1Member_10" xlink:type="arc" order="11" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueInputsLevel2Member" xlink:label="loc_us-gaapFairValueInputsLevel2Member_20" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapFairValueMeasurementsFairValueHierarchyDomain" xlink:to="loc_us-gaapFairValueInputsLevel2Member_20" xlink:type="arc" order="21" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueInputsLevel3Member" xlink:label="loc_us-gaapFairValueInputsLevel3Member_30" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapFairValueMeasurementsFairValueHierarchyDomain" xlink:to="loc_us-gaapFairValueInputsLevel3Member_30" xlink:type="arc" order="31" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CashAndCashEquivalentsFairValueDisclosure" xlink:label="loc_us-gaapCashAndCashEquivalentsFairValueDisclosure_130" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srtPlatformOperatorCryptoAssetLineItems" xlink:to="loc_us-gaapCashAndCashEquivalentsFairValueDisclosure_130" xlink:type="arc" order="0" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SecuritiesBorrowedFairValueDisclosure" xlink:label="loc_us-gaapSecuritiesBorrowedFairValueDisclosure_130" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srtPlatformOperatorCryptoAssetLineItems" xlink:to="loc_us-gaapSecuritiesBorrowedFairValueDisclosure_130" xlink:type="arc" order="1" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AssetsFairValueDisclosure" xlink:label="loc_us-gaapAssetsFairValueDisclosure_130" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srtPlatformOperatorCryptoAssetLineItems" xlink:to="loc_us-gaapAssetsFairValueDisclosure_130" xlink:type="arc" order="2" />
    </link:definitionLink>
    <link:definitionLink xlink:type="extended" xlink:role="http://genenta.com/role/SummaryOfSignificantAccountingPoliciesDetailsNarrative" xlink:title="999044 - Disclosure - Summary of significant accounting policies (Details Narrative)">
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PropertyPlantAndEquipmentLineItems" xlink:label="loc_us-gaapPropertyPlantAndEquipmentLineItems" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfPropertyPlantAndEquipmentTable" xlink:label="loc_us-gaapScheduleOfPropertyPlantAndEquipmentTable" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xbrldt:contextElement="segment" xlink:from="loc_us-gaapPropertyPlantAndEquipmentLineItems" xlink:to="loc_us-gaapScheduleOfPropertyPlantAndEquipmentTable" xlink:type="arc" order="10" xbrldt:closed="true" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StatementEquityComponentsAxis" xlink:label="loc_us-gaapStatementEquityComponentsAxis" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaapScheduleOfPropertyPlantAndEquipmentTable" xlink:to="loc_us-gaapStatementEquityComponentsAxis" xlink:type="arc" order="1" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_EquityComponentDomain" xlink:label="loc_us-gaapEquityComponentDomain" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaapStatementEquityComponentsAxis" xlink:to="loc_us-gaapEquityComponentDomain" xlink:type="arc" order="20" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_EquityComponentDomain" xlink:label="loc_us-gaapEquityComponentDomain_10" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xbrldt:contextElement="segment" xlink:from="loc_us-gaapStatementEquityComponentsAxis" xlink:to="loc_us-gaapEquityComponentDomain_10" xlink:type="arc" order="30" />
      <link:loc xlink:type="locator" xlink:href="gnta-20241231.xsd#GNTA_AmericanDepositorySharesMember" xlink:label="loc_GNTAAmericanDepositorySharesMember_30" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapEquityComponentDomain" xlink:to="loc_GNTAAmericanDepositorySharesMember_30" xlink:type="arc" order="31" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CommonStockMember" xlink:label="loc_us-gaapCommonStockMember_170" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapEquityComponentDomain" xlink:to="loc_us-gaapCommonStockMember_170" xlink:type="arc" order="172" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PlanNameAxis" xlink:label="loc_us-gaapPlanNameAxis" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaapScheduleOfPropertyPlantAndEquipmentTable" xlink:to="loc_us-gaapPlanNameAxis" xlink:type="arc" order="2" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PlanNameDomain" xlink:label="loc_us-gaapPlanNameDomain" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaapPlanNameAxis" xlink:to="loc_us-gaapPlanNameDomain" xlink:type="arc" order="20" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PlanNameDomain" xlink:label="loc_us-gaapPlanNameDomain_10" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xbrldt:contextElement="segment" xlink:from="loc_us-gaapPlanNameAxis" xlink:to="loc_us-gaapPlanNameDomain_10" xlink:type="arc" order="30" />
      <link:loc xlink:type="locator" xlink:href="gnta-20241231.xsd#GNTA_EquityIncentivePlanTwoThousandTwentyOneToTwoThousandTwentyFiveMember" xlink:label="loc_GNTAEquityIncentivePlanTwoThousandTwentyOneToTwoThousandTwentyFiveMember_50" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapPlanNameDomain" xlink:to="loc_GNTAEquityIncentivePlanTwoThousandTwentyOneToTwoThousandTwentyFiveMember_50" xlink:type="arc" order="51" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AwardTypeAxis" xlink:label="loc_us-gaapAwardTypeAxis" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaapScheduleOfPropertyPlantAndEquipmentTable" xlink:to="loc_us-gaapAwardTypeAxis" xlink:type="arc" order="3" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:label="loc_us-gaapShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaapAwardTypeAxis" xlink:to="loc_us-gaapShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:type="arc" order="20" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:label="loc_us-gaapShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_10" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xbrldt:contextElement="segment" xlink:from="loc_us-gaapAwardTypeAxis" xlink:to="loc_us-gaapShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_10" xlink:type="arc" order="30" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_EmployeeStockOptionMember" xlink:label="loc_us-gaapEmployeeStockOptionMember_60" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:to="loc_us-gaapEmployeeStockOptionMember_60" xlink:type="arc" order="61" />
      <link:loc xlink:type="locator" xlink:href="gnta-20241231.xsd#GNTA_UnderswritersCommonShareWarrantsMember" xlink:label="loc_GNTAUnderswritersCommonShareWarrantsMember_70" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:to="loc_GNTAUnderswritersCommonShareWarrantsMember_70" xlink:type="arc" order="71" />
      <link:loc xlink:type="locator" xlink:href="gnta-20241231.xsd#GNTA_UnderswritersWarrantsMember" xlink:label="loc_GNTAUnderswritersWarrantsMember_220" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:to="loc_GNTAUnderswritersWarrantsMember_220" xlink:type="arc" order="221" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis" xlink:label="loc_us-gaapAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaapScheduleOfPropertyPlantAndEquipmentTable" xlink:to="loc_us-gaapAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis" xlink:type="arc" order="4" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AntidilutiveSecuritiesNameDomain" xlink:label="loc_us-gaapAntidilutiveSecuritiesNameDomain" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaapAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis" xlink:to="loc_us-gaapAntidilutiveSecuritiesNameDomain" xlink:type="arc" order="20" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AntidilutiveSecuritiesNameDomain" xlink:label="loc_us-gaapAntidilutiveSecuritiesNameDomain_10" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xbrldt:contextElement="segment" xlink:from="loc_us-gaapAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis" xlink:to="loc_us-gaapAntidilutiveSecuritiesNameDomain_10" xlink:type="arc" order="30" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_EmployeeStockOptionMember" xlink:label="loc_us-gaapEmployeeStockOptionMember_80" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapAntidilutiveSecuritiesNameDomain" xlink:to="loc_us-gaapEmployeeStockOptionMember_80" xlink:type="arc" order="81" />
      <link:loc xlink:type="locator" xlink:href="gnta-20241231.xsd#GNTA_UnderswritersCommonShareWarrantsMember" xlink:label="loc_GNTAUnderswritersCommonShareWarrantsMember_90" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapAntidilutiveSecuritiesNameDomain" xlink:to="loc_GNTAUnderswritersCommonShareWarrantsMember_90" xlink:type="arc" order="91" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SubsidiarySaleOfStockAxis" xlink:label="loc_us-gaapSubsidiarySaleOfStockAxis" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaapScheduleOfPropertyPlantAndEquipmentTable" xlink:to="loc_us-gaapSubsidiarySaleOfStockAxis" xlink:type="arc" order="5" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SaleOfStockNameOfTransactionDomain" xlink:label="loc_us-gaapSaleOfStockNameOfTransactionDomain" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaapSubsidiarySaleOfStockAxis" xlink:to="loc_us-gaapSaleOfStockNameOfTransactionDomain" xlink:type="arc" order="20" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SaleOfStockNameOfTransactionDomain" xlink:label="loc_us-gaapSaleOfStockNameOfTransactionDomain_10" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xbrldt:contextElement="segment" xlink:from="loc_us-gaapSubsidiarySaleOfStockAxis" xlink:to="loc_us-gaapSaleOfStockNameOfTransactionDomain_10" xlink:type="arc" order="30" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_IPOMember" xlink:label="loc_us-gaapIPOMember_110" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapSaleOfStockNameOfTransactionDomain" xlink:to="loc_us-gaapIPOMember_110" xlink:type="arc" order="111" />
      <link:loc xlink:type="locator" xlink:href="gnta-20241231.xsd#GNTA_ATMOfferingCostsMember" xlink:label="loc_GNTAATMOfferingCostsMember_240" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapSaleOfStockNameOfTransactionDomain" xlink:to="loc_GNTAATMOfferingCostsMember_240" xlink:type="arc" order="241" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CashAndCashEquivalentsAxis" xlink:label="loc_us-gaapCashAndCashEquivalentsAxis" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaapScheduleOfPropertyPlantAndEquipmentTable" xlink:to="loc_us-gaapCashAndCashEquivalentsAxis" xlink:type="arc" order="6" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember" xlink:label="loc_us-gaapRestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaapCashAndCashEquivalentsAxis" xlink:to="loc_us-gaapRestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember" xlink:type="arc" order="20" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember" xlink:label="loc_us-gaapRestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember_10" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xbrldt:contextElement="segment" xlink:from="loc_us-gaapCashAndCashEquivalentsAxis" xlink:to="loc_us-gaapRestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember_10" xlink:type="arc" order="30" />
      <link:loc xlink:type="locator" xlink:href="gnta-20241231.xsd#GNTA_USTradePayablesMember" xlink:label="loc_GNTAUSTradePayablesMember_120" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapRestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember" xlink:to="loc_GNTAUSTradePayablesMember_120" xlink:type="arc" order="121" />
      <link:loc xlink:type="locator" xlink:href="gnta-20241231.xsd#GNTA_USTimeDepositsMember" xlink:label="loc_GNTAUSTimeDepositsMember_130" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapRestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember" xlink:to="loc_GNTAUSTimeDepositsMember_130" xlink:type="arc" order="131" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_RangeAxis" xlink:label="loc_srtRangeAxis" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaapScheduleOfPropertyPlantAndEquipmentTable" xlink:to="loc_srtRangeAxis" xlink:type="arc" order="7" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_RangeMember" xlink:label="loc_srtRangeMember" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srtRangeAxis" xlink:to="loc_srtRangeMember" xlink:type="arc" order="20" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_RangeMember" xlink:label="loc_srtRangeMember_10" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xbrldt:contextElement="segment" xlink:from="loc_srtRangeAxis" xlink:to="loc_srtRangeMember_10" xlink:type="arc" order="30" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_MaximumMember" xlink:label="loc_srtMaximumMember_140" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srtRangeMember" xlink:to="loc_srtMaximumMember_140" xlink:type="arc" order="141" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_MinimumMember" xlink:label="loc_srtMinimumMember_200" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srtRangeMember" xlink:to="loc_srtMinimumMember_200" xlink:type="arc" order="202" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_MarketableSecuritiesUnrealizedGainLoss" xlink:label="loc_us-gaapMarketableSecuritiesUnrealizedGainLoss_270" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapPropertyPlantAndEquipmentLineItems" xlink:to="loc_us-gaapMarketableSecuritiesUnrealizedGainLoss_270" xlink:type="arc" order="0" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_NetIncomeLoss" xlink:label="loc_us-gaapNetIncomeLoss_270" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapPropertyPlantAndEquipmentLineItems" xlink:to="loc_us-gaapNetIncomeLoss_270" xlink:type="arc" order="1" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_OtherComprehensiveIncomeLossNetOfTax" xlink:label="loc_us-gaapOtherComprehensiveIncomeLossNetOfTax_270" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapPropertyPlantAndEquipmentLineItems" xlink:to="loc_us-gaapOtherComprehensiveIncomeLossNetOfTax_270" xlink:type="arc" order="2" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ComprehensiveIncomeNetOfTax" xlink:label="loc_us-gaapComprehensiveIncomeNetOfTax_270" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapPropertyPlantAndEquipmentLineItems" xlink:to="loc_us-gaapComprehensiveIncomeNetOfTax_270" xlink:type="arc" order="3" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StockholdersEquityPeriodIncreaseDecrease" xlink:label="loc_us-gaapStockholdersEquityPeriodIncreaseDecrease_270" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapPropertyPlantAndEquipmentLineItems" xlink:to="loc_us-gaapStockholdersEquityPeriodIncreaseDecrease_270" xlink:type="arc" order="4" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CommonStockSharesAuthorized" xlink:label="loc_us-gaapCommonStockSharesAuthorized_270" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapPropertyPlantAndEquipmentLineItems" xlink:to="loc_us-gaapCommonStockSharesAuthorized_270" xlink:type="arc" order="5" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SharesIssued" xlink:label="loc_us-gaapSharesIssued_270" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapPropertyPlantAndEquipmentLineItems" xlink:to="loc_us-gaapSharesIssued_270" xlink:type="arc" order="6" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CommonStockSharesOutstanding" xlink:label="loc_us-gaapCommonStockSharesOutstanding_270" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapPropertyPlantAndEquipmentLineItems" xlink:to="loc_us-gaapCommonStockSharesOutstanding_270" xlink:type="arc" order="7" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CommonStockCapitalSharesReservedForFutureIssuance" xlink:label="loc_us-gaapCommonStockCapitalSharesReservedForFutureIssuance_270" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapPropertyPlantAndEquipmentLineItems" xlink:to="loc_us-gaapCommonStockCapitalSharesReservedForFutureIssuance_270" xlink:type="arc" order="8" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber" xlink:label="loc_us-gaapShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber_270" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapPropertyPlantAndEquipmentLineItems" xlink:to="loc_us-gaapShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber_270" xlink:type="arc" order="9" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount" xlink:label="loc_us-gaapAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount_270" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapPropertyPlantAndEquipmentLineItems" xlink:to="loc_us-gaapAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount_270" xlink:type="arc" order="10" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CumulativeTranslationAdjustmentNetOfTaxPeriodIncreaseDecrease" xlink:label="loc_us-gaapCumulativeTranslationAdjustmentNetOfTaxPeriodIncreaseDecrease_270" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapPropertyPlantAndEquipmentLineItems" xlink:to="loc_us-gaapCumulativeTranslationAdjustmentNetOfTaxPeriodIncreaseDecrease_270" xlink:type="arc" order="11" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ForeignCurrencyTransactionGainLossAfterTax" xlink:label="loc_us-gaapForeignCurrencyTransactionGainLossAfterTax_270" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapPropertyPlantAndEquipmentLineItems" xlink:to="loc_us-gaapForeignCurrencyTransactionGainLossAfterTax_270" xlink:type="arc" order="12" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ForeignCurrencyTransactionGainLossUnrealized" xlink:label="loc_us-gaapForeignCurrencyTransactionGainLossUnrealized_270" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapPropertyPlantAndEquipmentLineItems" xlink:to="loc_us-gaapForeignCurrencyTransactionGainLossUnrealized_270" xlink:type="arc" order="13" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ForeignCurrencyTransactionGainLossRealized" xlink:label="loc_us-gaapForeignCurrencyTransactionGainLossRealized_270" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapPropertyPlantAndEquipmentLineItems" xlink:to="loc_us-gaapForeignCurrencyTransactionGainLossRealized_270" xlink:type="arc" order="14" />
      <link:loc xlink:type="locator" xlink:href="gnta-20241231.xsd#GNTA_ForeignCurrencyTransactionGainRealized" xlink:label="loc_GNTAForeignCurrencyTransactionGainRealized_270" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapPropertyPlantAndEquipmentLineItems" xlink:to="loc_GNTAForeignCurrencyTransactionGainRealized_270" xlink:type="arc" order="15" />
      <link:loc xlink:type="locator" xlink:href="gnta-20241231.xsd#GNTA_ForeignCurrencyTransactionLossUnrealized" xlink:label="loc_GNTAForeignCurrencyTransactionLossUnrealized_270" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapPropertyPlantAndEquipmentLineItems" xlink:to="loc_GNTAForeignCurrencyTransactionLossUnrealized_270" xlink:type="arc" order="16" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_IncomeTaxReconciliationTaxCreditsResearch" xlink:label="loc_us-gaapIncomeTaxReconciliationTaxCreditsResearch_270" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapPropertyPlantAndEquipmentLineItems" xlink:to="loc_us-gaapIncomeTaxReconciliationTaxCreditsResearch_270" xlink:type="arc" order="17" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardExpirationPeriod" xlink:label="loc_us-gaapSharebasedCompensationArrangementBySharebasedPaymentAwardExpirationPeriod_270" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapPropertyPlantAndEquipmentLineItems" xlink:to="loc_us-gaapSharebasedCompensationArrangementBySharebasedPaymentAwardExpirationPeriod_270" xlink:type="arc" order="18" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized" xlink:label="loc_us-gaapShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized_270" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapPropertyPlantAndEquipmentLineItems" xlink:to="loc_us-gaapShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized_270" xlink:type="arc" order="19" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardPercentageOfOutstandingStockMaximum" xlink:label="loc_us-gaapShareBasedCompensationArrangementByShareBasedPaymentAwardPercentageOfOutstandingStockMaximum_270" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapPropertyPlantAndEquipmentLineItems" xlink:to="loc_us-gaapShareBasedCompensationArrangementByShareBasedPaymentAwardPercentageOfOutstandingStockMaximum_270" xlink:type="arc" order="20" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNumberOfSharesPeriodIncreaseDecrease" xlink:label="loc_us-gaapSharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNumberOfSharesPeriodIncreaseDecrease_270" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapPropertyPlantAndEquipmentLineItems" xlink:to="loc_us-gaapSharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNumberOfSharesPeriodIncreaseDecrease_270" xlink:type="arc" order="21" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant" xlink:label="loc_us-gaapShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant_270" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapPropertyPlantAndEquipmentLineItems" xlink:to="loc_us-gaapShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant_270" xlink:type="arc" order="22" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SharesOutstanding" xlink:label="loc_us-gaapSharesOutstanding_270" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapPropertyPlantAndEquipmentLineItems" xlink:to="loc_us-gaapSharesOutstanding_270" xlink:type="arc" order="23" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StockIssuedDuringPeriodSharesNewIssues" xlink:label="loc_us-gaapStockIssuedDuringPeriodSharesNewIssues_270" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapPropertyPlantAndEquipmentLineItems" xlink:to="loc_us-gaapStockIssuedDuringPeriodSharesNewIssues_270" xlink:type="arc" order="24" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1" xlink:label="loc_us-gaapClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1_270" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapPropertyPlantAndEquipmentLineItems" xlink:to="loc_us-gaapClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1_270" xlink:type="arc" order="25" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DeferredOfferingCosts" xlink:label="loc_us-gaapDeferredOfferingCosts_270" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapPropertyPlantAndEquipmentLineItems" xlink:to="loc_us-gaapDeferredOfferingCosts_270" xlink:type="arc" order="26" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DeferredIncome" xlink:label="loc_us-gaapDeferredIncome_270" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapPropertyPlantAndEquipmentLineItems" xlink:to="loc_us-gaapDeferredIncome_270" xlink:type="arc" order="27" />
    </link:definitionLink>
    <link:definitionLink xlink:type="extended" xlink:role="http://genenta.com/role/ScheduleOfEffectiveIncomeTaxRateReconciliationDetails" xlink:title="999045 - Disclosure - Schedule of effective income tax rate reconciliation (Details)" />
    <link:definitionLink xlink:type="extended" xlink:role="http://genenta.com/role/ScheduleOfDeferredTaxAssetsDetails" xlink:title="999046 - Disclosure - Schedule of deferred tax assets (Details)" />
    <link:definitionLink xlink:type="extended" xlink:role="http://genenta.com/role/ScheduleOfTaxLossCarryforwardsExpireDetails" xlink:title="999047 - Disclosure - Schedule of tax loss carryforwards expire (Details)">
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_OperatingLossCarryforwardsLineItems" xlink:label="loc_us-gaapOperatingLossCarryforwardsLineItems" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_OperatingLossCarryforwardsTable" xlink:label="loc_us-gaapOperatingLossCarryforwardsTable" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xbrldt:contextElement="segment" xlink:from="loc_us-gaapOperatingLossCarryforwardsLineItems" xlink:to="loc_us-gaapOperatingLossCarryforwardsTable" xlink:type="arc" order="10" xbrldt:closed="true" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_TaxPeriodAxis" xlink:label="loc_us-gaapTaxPeriodAxis" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaapOperatingLossCarryforwardsTable" xlink:to="loc_us-gaapTaxPeriodAxis" xlink:type="arc" order="1" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_TaxPeriodDomain" xlink:label="loc_us-gaapTaxPeriodDomain" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaapTaxPeriodAxis" xlink:to="loc_us-gaapTaxPeriodDomain" xlink:type="arc" order="20" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_TaxPeriodDomain" xlink:label="loc_us-gaapTaxPeriodDomain_10" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xbrldt:contextElement="segment" xlink:from="loc_us-gaapTaxPeriodAxis" xlink:to="loc_us-gaapTaxPeriodDomain_10" xlink:type="arc" order="30" />
      <link:loc xlink:type="locator" xlink:href="gnta-20241231.xsd#GNTA_NoExpirationDateMember" xlink:label="loc_GNTANoExpirationDateMember_0" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapTaxPeriodDomain" xlink:to="loc_GNTANoExpirationDateMember_0" xlink:type="arc" order="1" />
      <link:loc xlink:type="locator" xlink:href="gnta-20241231.xsd#GNTA_NoExpirationDateDlNinetyEightMember" xlink:label="loc_GNTANoExpirationDateDlNinetyEightMember_30" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapTaxPeriodDomain" xlink:to="loc_GNTANoExpirationDateDlNinetyEightMember_30" xlink:type="arc" order="31" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_OperatingLossCarryforwards" xlink:label="loc_us-gaapOperatingLossCarryforwards_100" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapOperatingLossCarryforwardsLineItems" xlink:to="loc_us-gaapOperatingLossCarryforwards_100" xlink:type="arc" order="0" />
    </link:definitionLink>
    <link:definitionLink xlink:type="extended" xlink:role="http://genenta.com/role/IncomeTaxesDetailsNarrative" xlink:title="999048 - Disclosure - Income taxes (Details Narrative)" />
    <link:definitionLink xlink:type="extended" xlink:role="http://genenta.com/role/ScheduleOfPrepaidExpensesAndOtherCurrentAssetsDetails" xlink:title="999049 - Disclosure - Schedule of prepaid expenses and other current assets (Details)" />
    <link:definitionLink xlink:type="extended" xlink:role="http://genenta.com/role/PrepaidExpensesAndOtherCurrentAssetsDetailsNarrative" xlink:title="999050 - Disclosure - Prepaid expenses and other current assets (Details Narrative)">
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RelatedPartyTransactionLineItems" xlink:label="loc_us-gaapRelatedPartyTransactionLineItems" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable" xlink:label="loc_us-gaapScheduleOfRelatedPartyTransactionsByRelatedPartyTable" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xbrldt:contextElement="segment" xlink:from="loc_us-gaapRelatedPartyTransactionLineItems" xlink:to="loc_us-gaapScheduleOfRelatedPartyTransactionsByRelatedPartyTable" xlink:type="arc" order="10" xbrldt:closed="true" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RelatedPartyTransactionAxis" xlink:label="loc_us-gaapRelatedPartyTransactionAxis" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaapScheduleOfRelatedPartyTransactionsByRelatedPartyTable" xlink:to="loc_us-gaapRelatedPartyTransactionAxis" xlink:type="arc" order="1" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RelatedPartyTransactionDomain" xlink:label="loc_us-gaapRelatedPartyTransactionDomain" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaapRelatedPartyTransactionAxis" xlink:to="loc_us-gaapRelatedPartyTransactionDomain" xlink:type="arc" order="20" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RelatedPartyTransactionDomain" xlink:label="loc_us-gaapRelatedPartyTransactionDomain_10" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xbrldt:contextElement="segment" xlink:from="loc_us-gaapRelatedPartyTransactionAxis" xlink:to="loc_us-gaapRelatedPartyTransactionDomain_10" xlink:type="arc" order="30" />
      <link:loc xlink:type="locator" xlink:href="gnta-20241231.xsd#GNTA_ResearchAndDevelopmentExpenseRelatedPartyMember" xlink:label="loc_GNTAResearchAndDevelopmentExpenseRelatedPartyMember_60" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapRelatedPartyTransactionDomain" xlink:to="loc_GNTAResearchAndDevelopmentExpenseRelatedPartyMember_60" xlink:type="arc" order="61" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InvestmentTypeAxis" xlink:label="loc_us-gaapInvestmentTypeAxis" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaapScheduleOfRelatedPartyTransactionsByRelatedPartyTable" xlink:to="loc_us-gaapInvestmentTypeAxis" xlink:type="arc" order="2" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InvestmentTypeCategorizationMember" xlink:label="loc_us-gaapInvestmentTypeCategorizationMember" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaapInvestmentTypeAxis" xlink:to="loc_us-gaapInvestmentTypeCategorizationMember" xlink:type="arc" order="20" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InvestmentTypeCategorizationMember" xlink:label="loc_us-gaapInvestmentTypeCategorizationMember_10" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xbrldt:contextElement="segment" xlink:from="loc_us-gaapInvestmentTypeAxis" xlink:to="loc_us-gaapInvestmentTypeCategorizationMember_10" xlink:type="arc" order="30" />
      <link:loc xlink:type="locator" xlink:href="gnta-20241231.xsd#GNTA_AllowanceForCorporateEquityMember" xlink:label="loc_GNTAAllowanceForCorporateEquityMember_90" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapInvestmentTypeCategorizationMember" xlink:to="loc_GNTAAllowanceForCorporateEquityMember_90" xlink:type="arc" order="91" />
      <link:loc xlink:type="locator" xlink:href="gnta-20241231.xsd#GNTA_AccruingFinancialInterestIncomeOnTimeDepositMember" xlink:label="loc_GNTAAccruingFinancialInterestIncomeOnTimeDepositMember_110" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapInvestmentTypeCategorizationMember" xlink:to="loc_GNTAAccruingFinancialInterestIncomeOnTimeDepositMember_110" xlink:type="arc" order="111" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_TitleOfIndividualAxis" xlink:label="loc_srtTitleOfIndividualAxis" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaapScheduleOfRelatedPartyTransactionsByRelatedPartyTable" xlink:to="loc_srtTitleOfIndividualAxis" xlink:type="arc" order="3" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_TitleOfIndividualWithRelationshipToEntityDomain" xlink:label="loc_srtTitleOfIndividualWithRelationshipToEntityDomain" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srtTitleOfIndividualAxis" xlink:to="loc_srtTitleOfIndividualWithRelationshipToEntityDomain" xlink:type="arc" order="20" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_TitleOfIndividualWithRelationshipToEntityDomain" xlink:label="loc_srtTitleOfIndividualWithRelationshipToEntityDomain_10" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xbrldt:contextElement="segment" xlink:from="loc_srtTitleOfIndividualAxis" xlink:to="loc_srtTitleOfIndividualWithRelationshipToEntityDomain_10" xlink:type="arc" order="30" />
      <link:loc xlink:type="locator" xlink:href="gnta-20241231.xsd#GNTA_DirectorAndOfficersMember" xlink:label="loc_GNTADirectorAndOfficersMember_120" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srtTitleOfIndividualWithRelationshipToEntityDomain" xlink:to="loc_GNTADirectorAndOfficersMember_120" xlink:type="arc" order="121" />
      <link:loc xlink:type="locator" xlink:href="gnta-20241231.xsd#GNTA_PercentageofValueAddedTax" xlink:label="loc_GNTAPercentageofValueAddedTax_140" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapRelatedPartyTransactionLineItems" xlink:to="loc_GNTAPercentageofValueAddedTax_140" xlink:type="arc" order="0" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_IncomeTaxReconciliationTaxCreditsResearch" xlink:label="loc_us-gaapIncomeTaxReconciliationTaxCreditsResearch_140" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapRelatedPartyTransactionLineItems" xlink:to="loc_us-gaapIncomeTaxReconciliationTaxCreditsResearch_140" xlink:type="arc" order="1" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_TaxesPayableCurrent" xlink:label="loc_us-gaapTaxesPayableCurrent_140" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapRelatedPartyTransactionLineItems" xlink:to="loc_us-gaapTaxesPayableCurrent_140" xlink:type="arc" order="2" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ResearchAndDevelopmentExpense" xlink:label="loc_us-gaapResearchAndDevelopmentExpense_140" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapRelatedPartyTransactionLineItems" xlink:to="loc_us-gaapResearchAndDevelopmentExpense_140" xlink:type="arc" order="3" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_OtherAssetsCurrent" xlink:label="loc_us-gaapOtherAssetsCurrent_140" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapRelatedPartyTransactionLineItems" xlink:to="loc_us-gaapOtherAssetsCurrent_140" xlink:type="arc" order="4" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_OtherPrepaidExpenseCurrent" xlink:label="loc_us-gaapOtherPrepaidExpenseCurrent_140" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapRelatedPartyTransactionLineItems" xlink:to="loc_us-gaapOtherPrepaidExpenseCurrent_140" xlink:type="arc" order="5" />
    </link:definitionLink>
    <link:definitionLink xlink:type="extended" xlink:role="http://genenta.com/role/ScheduleOfFixedAssetsnetDetails" xlink:title="999051 - Disclosure - Schedule of fixed assets,net (Details)" />
    <link:definitionLink xlink:type="extended" xlink:role="http://genenta.com/role/Non-currentAssetsRightOfUseRouDetailsNarrative" xlink:title="999052 - Disclosure - Non-current assets right of use (ROU) (Details Narrative)" />
    <link:definitionLink xlink:type="extended" xlink:role="http://genenta.com/role/ScheduleOfOtherNon-currentAssetsDetails" xlink:title="999053 - Disclosure - Schedule of other non-current assets (Details)">
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanDisclosureLineItems" xlink:label="loc_us-gaapDefinedBenefitPlanDisclosureLineItems" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable" xlink:label="loc_us-gaapScheduleOfDefinedBenefitPlansDisclosuresTable" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xbrldt:contextElement="segment" xlink:from="loc_us-gaapDefinedBenefitPlanDisclosureLineItems" xlink:to="loc_us-gaapScheduleOfDefinedBenefitPlansDisclosuresTable" xlink:type="arc" order="10" xbrldt:closed="true" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RelatedPartyTransactionsByRelatedPartyAxis" xlink:label="loc_us-gaapRelatedPartyTransactionsByRelatedPartyAxis" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaapScheduleOfDefinedBenefitPlansDisclosuresTable" xlink:to="loc_us-gaapRelatedPartyTransactionsByRelatedPartyAxis" xlink:type="arc" order="1" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RelatedPartyDomain" xlink:label="loc_us-gaapRelatedPartyDomain" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaapRelatedPartyTransactionsByRelatedPartyAxis" xlink:to="loc_us-gaapRelatedPartyDomain" xlink:type="arc" order="20" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RelatedPartyDomain" xlink:label="loc_us-gaapRelatedPartyDomain_10" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xbrldt:contextElement="segment" xlink:from="loc_us-gaapRelatedPartyTransactionsByRelatedPartyAxis" xlink:to="loc_us-gaapRelatedPartyDomain_10" xlink:type="arc" order="30" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_NonrelatedPartyMember" xlink:label="loc_us-gaapNonrelatedPartyMember_0" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapRelatedPartyDomain" xlink:to="loc_us-gaapNonrelatedPartyMember_0" xlink:type="arc" order="1" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ValueAddedTaxReceivableNoncurrent" xlink:label="loc_us-gaapValueAddedTaxReceivableNoncurrent_40" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapDefinedBenefitPlanDisclosureLineItems" xlink:to="loc_us-gaapValueAddedTaxReceivableNoncurrent_40" xlink:type="arc" order="0" />
      <link:loc xlink:type="locator" xlink:href="gnta-20241231.xsd#GNTA_ResearchAndDevelopmentTaxCreditNoncurrent" xlink:label="loc_GNTAResearchAndDevelopmentTaxCreditNoncurrent_40" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapDefinedBenefitPlanDisclosureLineItems" xlink:to="loc_GNTAResearchAndDevelopmentTaxCreditNoncurrent_40" xlink:type="arc" order="1" />
      <link:loc xlink:type="locator" xlink:href="gnta-20241231.xsd#GNTA_OtherNoncurrentAssets" xlink:label="loc_GNTAOtherNoncurrentAssets_40" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapDefinedBenefitPlanDisclosureLineItems" xlink:to="loc_GNTAOtherNoncurrentAssets_40" xlink:type="arc" order="2" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_OtherAssetsNoncurrent" xlink:label="loc_us-gaapOtherAssetsNoncurrent_40" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapDefinedBenefitPlanDisclosureLineItems" xlink:to="loc_us-gaapOtherAssetsNoncurrent_40" xlink:type="arc" order="3" />
    </link:definitionLink>
    <link:definitionLink xlink:type="extended" xlink:role="http://genenta.com/role/OtherNon-currentAssetsDetailsNarrative" xlink:title="999054 - Disclosure - Other non-current assets (Details Narrative)">
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StatementLineItems" xlink:label="loc_us-gaapStatementLineItems" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StatementTable" xlink:label="loc_us-gaapStatementTable" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xbrldt:contextElement="segment" xlink:from="loc_us-gaapStatementLineItems" xlink:to="loc_us-gaapStatementTable" xlink:type="arc" order="10" xbrldt:closed="true" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_BalanceSheetLocationAxis" xlink:label="loc_us-gaapBalanceSheetLocationAxis" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaapStatementTable" xlink:to="loc_us-gaapBalanceSheetLocationAxis" xlink:type="arc" order="1" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_BalanceSheetLocationDomain" xlink:label="loc_us-gaapBalanceSheetLocationDomain" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaapBalanceSheetLocationAxis" xlink:to="loc_us-gaapBalanceSheetLocationDomain" xlink:type="arc" order="20" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_BalanceSheetLocationDomain" xlink:label="loc_us-gaapBalanceSheetLocationDomain_10" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xbrldt:contextElement="segment" xlink:from="loc_us-gaapBalanceSheetLocationAxis" xlink:to="loc_us-gaapBalanceSheetLocationDomain_10" xlink:type="arc" order="30" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_OtherNoncurrentAssetsMember" xlink:label="loc_us-gaapOtherNoncurrentAssetsMember_10" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapBalanceSheetLocationDomain" xlink:to="loc_us-gaapOtherNoncurrentAssetsMember_10" xlink:type="arc" order="11" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RelatedPartyTransactionsByRelatedPartyAxis" xlink:label="loc_us-gaapRelatedPartyTransactionsByRelatedPartyAxis" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaapStatementTable" xlink:to="loc_us-gaapRelatedPartyTransactionsByRelatedPartyAxis" xlink:type="arc" order="2" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RelatedPartyDomain" xlink:label="loc_us-gaapRelatedPartyDomain" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaapRelatedPartyTransactionsByRelatedPartyAxis" xlink:to="loc_us-gaapRelatedPartyDomain" xlink:type="arc" order="20" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RelatedPartyDomain" xlink:label="loc_us-gaapRelatedPartyDomain_10" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xbrldt:contextElement="segment" xlink:from="loc_us-gaapRelatedPartyTransactionsByRelatedPartyAxis" xlink:to="loc_us-gaapRelatedPartyDomain_10" xlink:type="arc" order="30" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RelatedPartyMember" xlink:label="loc_us-gaapRelatedPartyMember_10" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapRelatedPartyDomain" xlink:to="loc_us-gaapRelatedPartyMember_10" xlink:type="arc" order="12" />
      <link:loc xlink:type="locator" xlink:href="gnta-20241231.xsd#GNTA_ProceedsFromValueAddedTaxRefundsReceivedLongTerm" xlink:label="loc_GNTAProceedsFromValueAddedTaxRefundsReceivedLongTerm_30" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapStatementLineItems" xlink:to="loc_GNTAProceedsFromValueAddedTaxRefundsReceivedLongTerm_30" xlink:type="arc" order="0" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SecurityDeposit" xlink:label="loc_us-gaapSecurityDeposit_30" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapStatementLineItems" xlink:to="loc_us-gaapSecurityDeposit_30" xlink:type="arc" order="1" />
    </link:definitionLink>
    <link:definitionLink xlink:type="extended" xlink:role="http://genenta.com/role/RetirementBenefitObligationDetailsNarrative" xlink:title="999055 - Disclosure - Retirement benefit obligation (Details Narrative)" />
    <link:definitionLink xlink:type="extended" xlink:role="http://genenta.com/role/ShareholdersEquityDetailsNarrative" xlink:title="999056 - Disclosure - Shareholders&#8217; equity (Details Narrative)">
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems" xlink:label="loc_us-gaapAccumulatedOtherComprehensiveIncomeLossLineItems" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossTable" xlink:label="loc_us-gaapAccumulatedOtherComprehensiveIncomeLossTable" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xbrldt:contextElement="segment" xlink:from="loc_us-gaapAccumulatedOtherComprehensiveIncomeLossLineItems" xlink:to="loc_us-gaapAccumulatedOtherComprehensiveIncomeLossTable" xlink:type="arc" order="10" xbrldt:closed="true" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StatementEquityComponentsAxis" xlink:label="loc_us-gaapStatementEquityComponentsAxis" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaapAccumulatedOtherComprehensiveIncomeLossTable" xlink:to="loc_us-gaapStatementEquityComponentsAxis" xlink:type="arc" order="1" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_EquityComponentDomain" xlink:label="loc_us-gaapEquityComponentDomain" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaapStatementEquityComponentsAxis" xlink:to="loc_us-gaapEquityComponentDomain" xlink:type="arc" order="20" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_EquityComponentDomain" xlink:label="loc_us-gaapEquityComponentDomain_10" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xbrldt:contextElement="segment" xlink:from="loc_us-gaapStatementEquityComponentsAxis" xlink:to="loc_us-gaapEquityComponentDomain_10" xlink:type="arc" order="30" />
      <link:loc xlink:type="locator" xlink:href="gnta-20241231.xsd#GNTA_AmericanDepositorySharesMember" xlink:label="loc_GNTAAmericanDepositorySharesMember_20" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapEquityComponentDomain" xlink:to="loc_GNTAAmericanDepositorySharesMember_20" xlink:type="arc" order="21" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PlanNameAxis" xlink:label="loc_us-gaapPlanNameAxis" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaapAccumulatedOtherComprehensiveIncomeLossTable" xlink:to="loc_us-gaapPlanNameAxis" xlink:type="arc" order="2" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PlanNameDomain" xlink:label="loc_us-gaapPlanNameDomain" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaapPlanNameAxis" xlink:to="loc_us-gaapPlanNameDomain" xlink:type="arc" order="20" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PlanNameDomain" xlink:label="loc_us-gaapPlanNameDomain_10" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xbrldt:contextElement="segment" xlink:from="loc_us-gaapPlanNameAxis" xlink:to="loc_us-gaapPlanNameDomain_10" xlink:type="arc" order="30" />
      <link:loc xlink:type="locator" xlink:href="gnta-20241231.xsd#GNTA_EquityIncentivePlanTwoThousandTwentyOneToTwoThousandTwentyFiveMember" xlink:label="loc_GNTAEquityIncentivePlanTwoThousandTwentyOneToTwoThousandTwentyFiveMember_80" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapPlanNameDomain" xlink:to="loc_GNTAEquityIncentivePlanTwoThousandTwentyOneToTwoThousandTwentyFiveMember_80" xlink:type="arc" order="81" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CommonStockSharesOutstanding" xlink:label="loc_us-gaapCommonStockSharesOutstanding_120" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapAccumulatedOtherComprehensiveIncomeLossLineItems" xlink:to="loc_us-gaapCommonStockSharesOutstanding_120" xlink:type="arc" order="0" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedInPeriodFairValue1" xlink:label="loc_us-gaapSharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedInPeriodFairValue1_120" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapAccumulatedOtherComprehensiveIncomeLossLineItems" xlink:to="loc_us-gaapSharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedInPeriodFairValue1_120" xlink:type="arc" order="1" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SharesIssued" xlink:label="loc_us-gaapSharesIssued_120" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapAccumulatedOtherComprehensiveIncomeLossLineItems" xlink:to="loc_us-gaapSharesIssued_120" xlink:type="arc" order="2" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StockIssued1" xlink:label="loc_us-gaapStockIssued1_120" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapAccumulatedOtherComprehensiveIncomeLossLineItems" xlink:to="loc_us-gaapStockIssued1_120" xlink:type="arc" order="3" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CommonStockCapitalSharesReservedForFutureIssuance" xlink:label="loc_us-gaapCommonStockCapitalSharesReservedForFutureIssuance_120" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapAccumulatedOtherComprehensiveIncomeLossLineItems" xlink:to="loc_us-gaapCommonStockCapitalSharesReservedForFutureIssuance_120" xlink:type="arc" order="4" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_WeightedAverageNumberOfSharesOutstandingBasic" xlink:label="loc_us-gaapWeightedAverageNumberOfSharesOutstandingBasic_120" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapAccumulatedOtherComprehensiveIncomeLossLineItems" xlink:to="loc_us-gaapWeightedAverageNumberOfSharesOutstandingBasic_120" xlink:type="arc" order="5" />
    </link:definitionLink>
    <link:definitionLink xlink:type="extended" xlink:role="http://genenta.com/role/ScheduleOfOutstandingStockOptionsDetails" xlink:title="999057 - Disclosure - Schedule of Outstanding Stock Options (Details)" />
    <link:definitionLink xlink:type="extended" xlink:role="http://genenta.com/role/ScheduleOfShareBasedCompensationExpensesDetails" xlink:title="999058 - Disclosure - Schedule of share based compensation expenses (Details)">
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems" xlink:label="loc_us-gaapEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTable" xlink:label="loc_us-gaapScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTable" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xbrldt:contextElement="segment" xlink:from="loc_us-gaapEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems" xlink:to="loc_us-gaapScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTable" xlink:type="arc" order="10" xbrldt:closed="true" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_IncomeStatementLocationAxis" xlink:label="loc_us-gaapIncomeStatementLocationAxis" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaapScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTable" xlink:to="loc_us-gaapIncomeStatementLocationAxis" xlink:type="arc" order="1" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_IncomeStatementLocationDomain" xlink:label="loc_us-gaapIncomeStatementLocationDomain" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaapIncomeStatementLocationAxis" xlink:to="loc_us-gaapIncomeStatementLocationDomain" xlink:type="arc" order="20" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_IncomeStatementLocationDomain" xlink:label="loc_us-gaapIncomeStatementLocationDomain_10" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xbrldt:contextElement="segment" xlink:from="loc_us-gaapIncomeStatementLocationAxis" xlink:to="loc_us-gaapIncomeStatementLocationDomain_10" xlink:type="arc" order="30" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ResearchAndDevelopmentExpenseMember" xlink:label="loc_us-gaapResearchAndDevelopmentExpenseMember_0" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapIncomeStatementLocationDomain" xlink:to="loc_us-gaapResearchAndDevelopmentExpenseMember_0" xlink:type="arc" order="1" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_GeneralAndAdministrativeExpenseMember" xlink:label="loc_us-gaapGeneralAndAdministrativeExpenseMember_60" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapIncomeStatementLocationDomain" xlink:to="loc_us-gaapGeneralAndAdministrativeExpenseMember_60" xlink:type="arc" order="61" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RelatedPartyTransactionsByRelatedPartyAxis" xlink:label="loc_us-gaapRelatedPartyTransactionsByRelatedPartyAxis" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaapScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTable" xlink:to="loc_us-gaapRelatedPartyTransactionsByRelatedPartyAxis" xlink:type="arc" order="2" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RelatedPartyDomain" xlink:label="loc_us-gaapRelatedPartyDomain" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaapRelatedPartyTransactionsByRelatedPartyAxis" xlink:to="loc_us-gaapRelatedPartyDomain" xlink:type="arc" order="20" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RelatedPartyDomain" xlink:label="loc_us-gaapRelatedPartyDomain_10" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xbrldt:contextElement="segment" xlink:from="loc_us-gaapRelatedPartyTransactionsByRelatedPartyAxis" xlink:to="loc_us-gaapRelatedPartyDomain_10" xlink:type="arc" order="30" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_NonrelatedPartyMember" xlink:label="loc_us-gaapNonrelatedPartyMember_0" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapRelatedPartyDomain" xlink:to="loc_us-gaapNonrelatedPartyMember_0" xlink:type="arc" order="2" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RelatedPartyMember" xlink:label="loc_us-gaapRelatedPartyMember_30" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapRelatedPartyDomain" xlink:to="loc_us-gaapRelatedPartyMember_30" xlink:type="arc" order="32" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AllocatedShareBasedCompensationExpense" xlink:label="loc_us-gaapAllocatedShareBasedCompensationExpense_190" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems" xlink:to="loc_us-gaapAllocatedShareBasedCompensationExpense_190" xlink:type="arc" order="0" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized" xlink:label="loc_us-gaapEmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized_190" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems" xlink:to="loc_us-gaapEmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized_190" xlink:type="arc" order="1" />
    </link:definitionLink>
    <link:definitionLink xlink:type="extended" xlink:role="http://genenta.com/role/Share-basedCompensationDetailsNarrative" xlink:title="999059 - Disclosure - Share-based compensation (Details Narrative)">
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StatementLineItems" xlink:label="loc_us-gaapStatementLineItems" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StatementTable" xlink:label="loc_us-gaapStatementTable" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xbrldt:contextElement="segment" xlink:from="loc_us-gaapStatementLineItems" xlink:to="loc_us-gaapStatementTable" xlink:type="arc" order="10" xbrldt:closed="true" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_TitleOfIndividualAxis" xlink:label="loc_srtTitleOfIndividualAxis" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaapStatementTable" xlink:to="loc_srtTitleOfIndividualAxis" xlink:type="arc" order="1" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_TitleOfIndividualWithRelationshipToEntityDomain" xlink:label="loc_srtTitleOfIndividualWithRelationshipToEntityDomain" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srtTitleOfIndividualAxis" xlink:to="loc_srtTitleOfIndividualWithRelationshipToEntityDomain" xlink:type="arc" order="20" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_TitleOfIndividualWithRelationshipToEntityDomain" xlink:label="loc_srtTitleOfIndividualWithRelationshipToEntityDomain_10" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xbrldt:contextElement="segment" xlink:from="loc_srtTitleOfIndividualAxis" xlink:to="loc_srtTitleOfIndividualWithRelationshipToEntityDomain_10" xlink:type="arc" order="30" />
      <link:loc xlink:type="locator" xlink:href="gnta-20241231.xsd#GNTA_DirectorAndOfficersAndEmployeeMember" xlink:label="loc_GNTADirectorAndOfficersAndEmployeeMember_30" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srtTitleOfIndividualWithRelationshipToEntityDomain" xlink:to="loc_GNTADirectorAndOfficersAndEmployeeMember_30" xlink:type="arc" order="31" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_DirectorMember" xlink:label="loc_srtDirectorMember_70" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srtTitleOfIndividualWithRelationshipToEntityDomain" xlink:to="loc_srtDirectorMember_70" xlink:type="arc" order="71" />
      <link:loc xlink:type="locator" xlink:href="gnta-20241231.xsd#GNTA_OfficersAndEmployeeMember" xlink:label="loc_GNTAOfficersAndEmployeeMember_100" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srtTitleOfIndividualWithRelationshipToEntityDomain" xlink:to="loc_GNTAOfficersAndEmployeeMember_100" xlink:type="arc" order="101" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardSharesIssuedInPeriod" xlink:label="loc_us-gaapShareBasedCompensationArrangementByShareBasedPaymentAwardSharesIssuedInPeriod_170" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapStatementLineItems" xlink:to="loc_us-gaapShareBasedCompensationArrangementByShareBasedPaymentAwardSharesIssuedInPeriod_170" xlink:type="arc" order="0" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExercisePrice" xlink:label="loc_us-gaapShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExercisePrice_170" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapStatementLineItems" xlink:to="loc_us-gaapShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExercisePrice_170" xlink:type="arc" order="1" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardTermsOfAward" xlink:label="loc_us-gaapShareBasedCompensationArrangementByShareBasedPaymentAwardTermsOfAward_170" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapStatementLineItems" xlink:to="loc_us-gaapShareBasedCompensationArrangementByShareBasedPaymentAwardTermsOfAward_170" xlink:type="arc" order="2" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardSharesPurchasedForAward" xlink:label="loc_us-gaapShareBasedCompensationArrangementByShareBasedPaymentAwardSharesPurchasedForAward_170" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapStatementLineItems" xlink:to="loc_us-gaapShareBasedCompensationArrangementByShareBasedPaymentAwardSharesPurchasedForAward_170" xlink:type="arc" order="3" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant" xlink:label="loc_us-gaapShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant_170" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapStatementLineItems" xlink:to="loc_us-gaapShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant_170" xlink:type="arc" order="4" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross" xlink:label="loc_us-gaapShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross_170" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapStatementLineItems" xlink:to="loc_us-gaapShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross_170" xlink:type="arc" order="5" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber" xlink:label="loc_us-gaapShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber_170" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapStatementLineItems" xlink:to="loc_us-gaapShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber_170" xlink:type="arc" order="6" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresAndExpirationsInPeriod" xlink:label="loc_us-gaapShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresAndExpirationsInPeriod_170" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapStatementLineItems" xlink:to="loc_us-gaapShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresAndExpirationsInPeriod_170" xlink:type="arc" order="7" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedInPeriodFairValue1" xlink:label="loc_us-gaapSharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedInPeriodFairValue1_170" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapStatementLineItems" xlink:to="loc_us-gaapSharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedInPeriodFairValue1_170" xlink:type="arc" order="8" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized" xlink:label="loc_us-gaapEmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized_170" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapStatementLineItems" xlink:to="loc_us-gaapEmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized_170" xlink:type="arc" order="9" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice" xlink:label="loc_us-gaapShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice_170" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapStatementLineItems" xlink:to="loc_us-gaapShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice_170" xlink:type="arc" order="10" />
    </link:definitionLink>
    <link:definitionLink xlink:type="extended" xlink:role="http://genenta.com/role/ScheduleOfAccumulatedOtherComprehensiveIncomeDetails" xlink:title="999060 - Disclosure - Schedule of Accumulated Other Comprehensive Income (Details)">
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems" xlink:label="loc_us-gaapAccumulatedOtherComprehensiveIncomeLossLineItems" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossTable" xlink:label="loc_us-gaapAccumulatedOtherComprehensiveIncomeLossTable" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xbrldt:contextElement="segment" xlink:from="loc_us-gaapAccumulatedOtherComprehensiveIncomeLossLineItems" xlink:to="loc_us-gaapAccumulatedOtherComprehensiveIncomeLossTable" xlink:type="arc" order="10" xbrldt:closed="true" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StatementEquityComponentsAxis" xlink:label="loc_us-gaapStatementEquityComponentsAxis" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaapAccumulatedOtherComprehensiveIncomeLossTable" xlink:to="loc_us-gaapStatementEquityComponentsAxis" xlink:type="arc" order="1" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_EquityComponentDomain" xlink:label="loc_us-gaapEquityComponentDomain" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaapStatementEquityComponentsAxis" xlink:to="loc_us-gaapEquityComponentDomain" xlink:type="arc" order="20" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_EquityComponentDomain" xlink:label="loc_us-gaapEquityComponentDomain_10" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xbrldt:contextElement="segment" xlink:from="loc_us-gaapStatementEquityComponentsAxis" xlink:to="loc_us-gaapEquityComponentDomain_10" xlink:type="arc" order="30" />
      <link:loc xlink:type="locator" xlink:href="gnta-20241231.xsd#GNTA_AccumulatedNetUnrealizedGainLossMember" xlink:label="loc_GNTAAccumulatedNetUnrealizedGainLossMember_0" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapEquityComponentDomain" xlink:to="loc_GNTAAccumulatedNetUnrealizedGainLossMember_0" xlink:type="arc" order="1" />
      <link:loc xlink:type="locator" xlink:href="gnta-20241231.xsd#GNTA_AccumulatedTranslationAdjustmentsMember" xlink:label="loc_GNTAAccumulatedTranslationAdjustmentsMember_10" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapEquityComponentDomain" xlink:to="loc_GNTAAccumulatedTranslationAdjustmentsMember_10" xlink:type="arc" order="11" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax" xlink:label="loc_us-gaapAccumulatedOtherComprehensiveIncomeLossNetOfTax_100" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapAccumulatedOtherComprehensiveIncomeLossLineItems" xlink:to="loc_us-gaapAccumulatedOtherComprehensiveIncomeLossNetOfTax_100" xlink:type="arc" order="0" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesNetOfTax" xlink:label="loc_us-gaapOtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesNetOfTax_100" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapAccumulatedOtherComprehensiveIncomeLossLineItems" xlink:to="loc_us-gaapOtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesNetOfTax_100" xlink:type="arc" order="1" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_MarketableSecuritiesGainLossExcludingOtherThanTemporaryImpairments" xlink:label="loc_us-gaapMarketableSecuritiesGainLossExcludingOtherThanTemporaryImpairments_100" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapAccumulatedOtherComprehensiveIncomeLossLineItems" xlink:to="loc_us-gaapMarketableSecuritiesGainLossExcludingOtherThanTemporaryImpairments_100" xlink:type="arc" order="2" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CumulativeTranslationAdjustmentNetOfTaxPeriodIncreaseDecrease" xlink:label="loc_us-gaapCumulativeTranslationAdjustmentNetOfTaxPeriodIncreaseDecrease_100" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapAccumulatedOtherComprehensiveIncomeLossLineItems" xlink:to="loc_us-gaapCumulativeTranslationAdjustmentNetOfTaxPeriodIncreaseDecrease_100" xlink:type="arc" order="3" />
    </link:definitionLink>
    <link:definitionLink xlink:type="extended" xlink:role="http://genenta.com/role/AccumulatedOtherComprehensiveIncomeDetailsNarrative" xlink:title="999061 - Disclosure - Accumulated other comprehensive income (Details Narrative)" />
    <link:definitionLink xlink:type="extended" xlink:role="http://genenta.com/role/ScheduleOfThirdPartyAndRelatedPartyExpensesDetails" xlink:title="999062 - Disclosure - Schedule of third party and related party expenses (Details)">
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RelatedPartyTransactionLineItems" xlink:label="loc_us-gaapRelatedPartyTransactionLineItems" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable" xlink:label="loc_us-gaapScheduleOfRelatedPartyTransactionsByRelatedPartyTable" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xbrldt:contextElement="segment" xlink:from="loc_us-gaapRelatedPartyTransactionLineItems" xlink:to="loc_us-gaapScheduleOfRelatedPartyTransactionsByRelatedPartyTable" xlink:type="arc" order="10" xbrldt:closed="true" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RelatedPartyTransactionsByRelatedPartyAxis" xlink:label="loc_us-gaapRelatedPartyTransactionsByRelatedPartyAxis" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaapScheduleOfRelatedPartyTransactionsByRelatedPartyTable" xlink:to="loc_us-gaapRelatedPartyTransactionsByRelatedPartyAxis" xlink:type="arc" order="1" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RelatedPartyDomain" xlink:label="loc_us-gaapRelatedPartyDomain" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaapRelatedPartyTransactionsByRelatedPartyAxis" xlink:to="loc_us-gaapRelatedPartyDomain" xlink:type="arc" order="20" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RelatedPartyDomain" xlink:label="loc_us-gaapRelatedPartyDomain_10" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xbrldt:contextElement="segment" xlink:from="loc_us-gaapRelatedPartyTransactionsByRelatedPartyAxis" xlink:to="loc_us-gaapRelatedPartyDomain_10" xlink:type="arc" order="30" />
      <link:loc xlink:type="locator" xlink:href="gnta-20241231.xsd#GNTA_ThirdPartiesMember" xlink:label="loc_GNTAThirdPartiesMember_0" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapRelatedPartyDomain" xlink:to="loc_GNTAThirdPartiesMember_0" xlink:type="arc" order="1" />
      <link:loc xlink:type="locator" xlink:href="gnta-20241231.xsd#GNTA_RelatedPartiesMember" xlink:label="loc_GNTARelatedPartiesMember_10" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapRelatedPartyDomain" xlink:to="loc_GNTARelatedPartiesMember_10" xlink:type="arc" order="11" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_ProductOrServiceAxis" xlink:label="loc_srtProductOrServiceAxis" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaapScheduleOfRelatedPartyTransactionsByRelatedPartyTable" xlink:to="loc_srtProductOrServiceAxis" xlink:type="arc" order="2" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_ProductsAndServicesDomain" xlink:label="loc_srtProductsAndServicesDomain" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srtProductOrServiceAxis" xlink:to="loc_srtProductsAndServicesDomain" xlink:type="arc" order="20" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_ProductsAndServicesDomain" xlink:label="loc_srtProductsAndServicesDomain_10" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xbrldt:contextElement="segment" xlink:from="loc_srtProductOrServiceAxis" xlink:to="loc_srtProductsAndServicesDomain_10" xlink:type="arc" order="30" />
      <link:loc xlink:type="locator" xlink:href="gnta-20241231.xsd#GNTA_ConsultantsAndOtherThirdPartiesMember" xlink:label="loc_GNTAConsultantsAndOtherThirdPartiesMember_0" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srtProductsAndServicesDomain" xlink:to="loc_GNTAConsultantsAndOtherThirdPartiesMember_0" xlink:type="arc" order="2" />
      <link:loc xlink:type="locator" xlink:href="gnta-20241231.xsd#GNTA_MaterialsAndSuppliesMember" xlink:label="loc_GNTAMaterialsAndSuppliesMember_30" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srtProductsAndServicesDomain" xlink:to="loc_GNTAMaterialsAndSuppliesMember_30" xlink:type="arc" order="32" />
      <link:loc xlink:type="locator" xlink:href="gnta-20241231.xsd#GNTA_CompensationMember" xlink:label="loc_GNTACompensationMember_60" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srtProductsAndServicesDomain" xlink:to="loc_GNTACompensationMember_60" xlink:type="arc" order="62" />
      <link:loc xlink:type="locator" xlink:href="gnta-20241231.xsd#GNTA_TravelAndEntertainmentMember" xlink:label="loc_GNTATravelAndEntertainmentMember_90" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srtProductsAndServicesDomain" xlink:to="loc_GNTATravelAndEntertainmentMember_90" xlink:type="arc" order="92" />
      <link:loc xlink:type="locator" xlink:href="gnta-20241231.xsd#GNTA_OtherMember" xlink:label="loc_GNTAOtherMember_120" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srtProductsAndServicesDomain" xlink:to="loc_GNTAOtherMember_120" xlink:type="arc" order="122" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ResearchAndDevelopmentExpense" xlink:label="loc_us-gaapResearchAndDevelopmentExpense_520" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapRelatedPartyTransactionLineItems" xlink:to="loc_us-gaapResearchAndDevelopmentExpense_520" xlink:type="arc" order="0" />
    </link:definitionLink>
    <link:definitionLink xlink:type="extended" xlink:role="http://genenta.com/role/ScheduleOfThirdPartyAndGeneralAndAdministrativeExpensesDetails" xlink:title="999063 - Disclosure - Schedule of third party and general and administrative expenses (Details)">
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RelatedPartyTransactionLineItems" xlink:label="loc_us-gaapRelatedPartyTransactionLineItems" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable" xlink:label="loc_us-gaapScheduleOfRelatedPartyTransactionsByRelatedPartyTable" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xbrldt:contextElement="segment" xlink:from="loc_us-gaapRelatedPartyTransactionLineItems" xlink:to="loc_us-gaapScheduleOfRelatedPartyTransactionsByRelatedPartyTable" xlink:type="arc" order="10" xbrldt:closed="true" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RelatedPartyTransactionAxis" xlink:label="loc_us-gaapRelatedPartyTransactionAxis" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaapScheduleOfRelatedPartyTransactionsByRelatedPartyTable" xlink:to="loc_us-gaapRelatedPartyTransactionAxis" xlink:type="arc" order="1" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RelatedPartyTransactionDomain" xlink:label="loc_us-gaapRelatedPartyTransactionDomain" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaapRelatedPartyTransactionAxis" xlink:to="loc_us-gaapRelatedPartyTransactionDomain" xlink:type="arc" order="20" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RelatedPartyTransactionDomain" xlink:label="loc_us-gaapRelatedPartyTransactionDomain_10" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xbrldt:contextElement="segment" xlink:from="loc_us-gaapRelatedPartyTransactionAxis" xlink:to="loc_us-gaapRelatedPartyTransactionDomain_10" xlink:type="arc" order="30" />
      <link:loc xlink:type="locator" xlink:href="gnta-20241231.xsd#GNTA_ThirdPartiesMember" xlink:label="loc_GNTAThirdPartiesMember_0" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapRelatedPartyTransactionDomain" xlink:to="loc_GNTAThirdPartiesMember_0" xlink:type="arc" order="1" />
      <link:loc xlink:type="locator" xlink:href="gnta-20241231.xsd#GNTA_RelatedPartiesMember" xlink:label="loc_GNTARelatedPartiesMember_10" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapRelatedPartyTransactionDomain" xlink:to="loc_GNTARelatedPartiesMember_10" xlink:type="arc" order="11" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_ProductOrServiceAxis" xlink:label="loc_srtProductOrServiceAxis" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaapScheduleOfRelatedPartyTransactionsByRelatedPartyTable" xlink:to="loc_srtProductOrServiceAxis" xlink:type="arc" order="2" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_ProductsAndServicesDomain" xlink:label="loc_srtProductsAndServicesDomain" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srtProductOrServiceAxis" xlink:to="loc_srtProductsAndServicesDomain" xlink:type="arc" order="20" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_ProductsAndServicesDomain" xlink:label="loc_srtProductsAndServicesDomain_10" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xbrldt:contextElement="segment" xlink:from="loc_srtProductOrServiceAxis" xlink:to="loc_srtProductsAndServicesDomain_10" xlink:type="arc" order="30" />
      <link:loc xlink:type="locator" xlink:href="gnta-20241231.xsd#GNTA_CompensationMember" xlink:label="loc_GNTACompensationMember_0" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srtProductsAndServicesDomain" xlink:to="loc_GNTACompensationMember_0" xlink:type="arc" order="2" />
      <link:loc xlink:type="locator" xlink:href="gnta-20241231.xsd#GNTA_AccountingLegalAndOtherProfessionalMember" xlink:label="loc_GNTAAccountingLegalAndOtherProfessionalMember_30" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srtProductsAndServicesDomain" xlink:to="loc_GNTAAccountingLegalAndOtherProfessionalMember_30" xlink:type="arc" order="32" />
      <link:loc xlink:type="locator" xlink:href="gnta-20241231.xsd#GNTA_CommunicationAndITRelatedMember" xlink:label="loc_GNTACommunicationAndITRelatedMember_60" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srtProductsAndServicesDomain" xlink:to="loc_GNTACommunicationAndITRelatedMember_60" xlink:type="arc" order="62" />
      <link:loc xlink:type="locator" xlink:href="gnta-20241231.xsd#GNTA_FacilityAndInsuranceRelatedMember" xlink:label="loc_GNTAFacilityAndInsuranceRelatedMember_80" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srtProductsAndServicesDomain" xlink:to="loc_GNTAFacilityAndInsuranceRelatedMember_80" xlink:type="arc" order="82" />
      <link:loc xlink:type="locator" xlink:href="gnta-20241231.xsd#GNTA_ConsultantsAndOtherThirdPartiesMember" xlink:label="loc_GNTAConsultantsAndOtherThirdPartiesMember_110" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srtProductsAndServicesDomain" xlink:to="loc_GNTAConsultantsAndOtherThirdPartiesMember_110" xlink:type="arc" order="112" />
      <link:loc xlink:type="locator" xlink:href="gnta-20241231.xsd#GNTA_OtherMember" xlink:label="loc_GNTAOtherMember_140" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srtProductsAndServicesDomain" xlink:to="loc_GNTAOtherMember_140" xlink:type="arc" order="142" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_GeneralAndAdministrativeExpense" xlink:label="loc_us-gaapGeneralAndAdministrativeExpense_620" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapRelatedPartyTransactionLineItems" xlink:to="loc_us-gaapGeneralAndAdministrativeExpense_620" xlink:type="arc" order="0" />
    </link:definitionLink>
    <link:definitionLink xlink:type="extended" xlink:role="http://genenta.com/role/ScheduleOfAccountsPayableToRelatedPartiesDetails" xlink:title="999064 - Disclosure - Schedule of accounts payable to related parties (Details)">
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RelatedPartyTransactionLineItems" xlink:label="loc_us-gaapRelatedPartyTransactionLineItems" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable" xlink:label="loc_us-gaapScheduleOfRelatedPartyTransactionsByRelatedPartyTable" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xbrldt:contextElement="segment" xlink:from="loc_us-gaapRelatedPartyTransactionLineItems" xlink:to="loc_us-gaapScheduleOfRelatedPartyTransactionsByRelatedPartyTable" xlink:type="arc" order="10" xbrldt:closed="true" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RelatedPartyTransactionAxis" xlink:label="loc_us-gaapRelatedPartyTransactionAxis" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaapScheduleOfRelatedPartyTransactionsByRelatedPartyTable" xlink:to="loc_us-gaapRelatedPartyTransactionAxis" xlink:type="arc" order="1" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RelatedPartyTransactionDomain" xlink:label="loc_us-gaapRelatedPartyTransactionDomain" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaapRelatedPartyTransactionAxis" xlink:to="loc_us-gaapRelatedPartyTransactionDomain" xlink:type="arc" order="20" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RelatedPartyTransactionDomain" xlink:label="loc_us-gaapRelatedPartyTransactionDomain_10" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xbrldt:contextElement="segment" xlink:from="loc_us-gaapRelatedPartyTransactionAxis" xlink:to="loc_us-gaapRelatedPartyTransactionDomain_10" xlink:type="arc" order="30" />
      <link:loc xlink:type="locator" xlink:href="gnta-20241231.xsd#GNTA_SanRaffaeleHospitalOSRMember" xlink:label="loc_GNTASanRaffaeleHospitalOSRMember_0" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapRelatedPartyTransactionDomain" xlink:to="loc_GNTASanRaffaeleHospitalOSRMember_0" xlink:type="arc" order="1" />
      <link:loc xlink:type="locator" xlink:href="gnta-20241231.xsd#GNTA_CarloRussoMember" xlink:label="loc_GNTACarloRussoMember_30" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapRelatedPartyTransactionDomain" xlink:to="loc_GNTACarloRussoMember_30" xlink:type="arc" order="31" />
      <link:loc xlink:type="locator" xlink:href="gnta-20241231.xsd#GNTA_RichardSlanskyMember" xlink:label="loc_GNTARichardSlanskyMember_60" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapRelatedPartyTransactionDomain" xlink:to="loc_GNTARichardSlanskyMember_60" xlink:type="arc" order="61" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RelatedPartyTransactionsByRelatedPartyAxis" xlink:label="loc_us-gaapRelatedPartyTransactionsByRelatedPartyAxis" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaapScheduleOfRelatedPartyTransactionsByRelatedPartyTable" xlink:to="loc_us-gaapRelatedPartyTransactionsByRelatedPartyAxis" xlink:type="arc" order="2" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RelatedPartyDomain" xlink:label="loc_us-gaapRelatedPartyDomain" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaapRelatedPartyTransactionsByRelatedPartyAxis" xlink:to="loc_us-gaapRelatedPartyDomain" xlink:type="arc" order="20" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RelatedPartyDomain" xlink:label="loc_us-gaapRelatedPartyDomain_10" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xbrldt:contextElement="segment" xlink:from="loc_us-gaapRelatedPartyTransactionsByRelatedPartyAxis" xlink:to="loc_us-gaapRelatedPartyDomain_10" xlink:type="arc" order="30" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RelatedPartyMember" xlink:label="loc_us-gaapRelatedPartyMember_0" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapRelatedPartyDomain" xlink:to="loc_us-gaapRelatedPartyMember_0" xlink:type="arc" order="2" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AccountsPayableCurrent" xlink:label="loc_us-gaapAccountsPayableCurrent_130" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapRelatedPartyTransactionLineItems" xlink:to="loc_us-gaapAccountsPayableCurrent_130" xlink:type="arc" order="0" />
    </link:definitionLink>
    <link:definitionLink xlink:type="extended" xlink:role="http://genenta.com/role/ScheduleOfAccruedExpensesToRelatedPartiesDetails" xlink:title="999065 - Disclosure - Schedule of accrued expenses to related parties (Details)">
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RelatedPartyTransactionLineItems" xlink:label="loc_us-gaapRelatedPartyTransactionLineItems" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable" xlink:label="loc_us-gaapScheduleOfRelatedPartyTransactionsByRelatedPartyTable" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xbrldt:contextElement="segment" xlink:from="loc_us-gaapRelatedPartyTransactionLineItems" xlink:to="loc_us-gaapScheduleOfRelatedPartyTransactionsByRelatedPartyTable" xlink:type="arc" order="10" xbrldt:closed="true" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RelatedPartyTransactionAxis" xlink:label="loc_us-gaapRelatedPartyTransactionAxis" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaapScheduleOfRelatedPartyTransactionsByRelatedPartyTable" xlink:to="loc_us-gaapRelatedPartyTransactionAxis" xlink:type="arc" order="1" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RelatedPartyTransactionDomain" xlink:label="loc_us-gaapRelatedPartyTransactionDomain" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaapRelatedPartyTransactionAxis" xlink:to="loc_us-gaapRelatedPartyTransactionDomain" xlink:type="arc" order="20" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RelatedPartyTransactionDomain" xlink:label="loc_us-gaapRelatedPartyTransactionDomain_10" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xbrldt:contextElement="segment" xlink:from="loc_us-gaapRelatedPartyTransactionAxis" xlink:to="loc_us-gaapRelatedPartyTransactionDomain_10" xlink:type="arc" order="30" />
      <link:loc xlink:type="locator" xlink:href="gnta-20241231.xsd#GNTA_SanRaffaeleHospitalOSRMember" xlink:label="loc_GNTASanRaffaeleHospitalOSRMember_0" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapRelatedPartyTransactionDomain" xlink:to="loc_GNTASanRaffaeleHospitalOSRMember_0" xlink:type="arc" order="1" />
      <link:loc xlink:type="locator" xlink:href="gnta-20241231.xsd#GNTA_PierluigiParacchiMember" xlink:label="loc_GNTAPierluigiParacchiMember_30" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapRelatedPartyTransactionDomain" xlink:to="loc_GNTAPierluigiParacchiMember_30" xlink:type="arc" order="31" />
      <link:loc xlink:type="locator" xlink:href="gnta-20241231.xsd#GNTA_RichardSlanskyMember" xlink:label="loc_GNTARichardSlanskyMember_60" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapRelatedPartyTransactionDomain" xlink:to="loc_GNTARichardSlanskyMember_60" xlink:type="arc" order="61" />
      <link:loc xlink:type="locator" xlink:href="gnta-20241231.xsd#GNTA_CarloRussoMember" xlink:label="loc_GNTACarloRussoMember_90" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapRelatedPartyTransactionDomain" xlink:to="loc_GNTACarloRussoMember_90" xlink:type="arc" order="91" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AccruedLiabilitiesCurrentAndNoncurrent" xlink:label="loc_us-gaapAccruedLiabilitiesCurrentAndNoncurrent_160" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapRelatedPartyTransactionLineItems" xlink:to="loc_us-gaapAccruedLiabilitiesCurrentAndNoncurrent_160" xlink:type="arc" order="0" />
    </link:definitionLink>
    <link:definitionLink xlink:type="extended" xlink:role="http://genenta.com/role/RelatedPartiesDetailsNarrative" xlink:title="999066 - Disclosure - Related parties (Details Narrative)">
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StatementLineItems" xlink:label="loc_us-gaapStatementLineItems" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StatementTable" xlink:label="loc_us-gaapStatementTable" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xbrldt:contextElement="segment" xlink:from="loc_us-gaapStatementLineItems" xlink:to="loc_us-gaapStatementTable" xlink:type="arc" order="10" xbrldt:closed="true" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_RangeAxis" xlink:label="loc_srtRangeAxis" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaapStatementTable" xlink:to="loc_srtRangeAxis" xlink:type="arc" order="1" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_RangeMember" xlink:label="loc_srtRangeMember" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srtRangeAxis" xlink:to="loc_srtRangeMember" xlink:type="arc" order="20" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_RangeMember" xlink:label="loc_srtRangeMember_10" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xbrldt:contextElement="segment" xlink:from="loc_srtRangeAxis" xlink:to="loc_srtRangeMember_10" xlink:type="arc" order="30" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_MinimumMember" xlink:label="loc_srtMinimumMember_60" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srtRangeMember" xlink:to="loc_srtMinimumMember_60" xlink:type="arc" order="61" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_MaximumMember" xlink:label="loc_srtMaximumMember_70" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srtRangeMember" xlink:to="loc_srtMaximumMember_70" xlink:type="arc" order="71" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_TypeOfArrangementAxis" xlink:label="loc_us-gaapTypeOfArrangementAxis" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaapStatementTable" xlink:to="loc_us-gaapTypeOfArrangementAxis" xlink:type="arc" order="2" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ArrangementsAndNonarrangementTransactionsMember" xlink:label="loc_us-gaapArrangementsAndNonarrangementTransactionsMember" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaapTypeOfArrangementAxis" xlink:to="loc_us-gaapArrangementsAndNonarrangementTransactionsMember" xlink:type="arc" order="20" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ArrangementsAndNonarrangementTransactionsMember" xlink:label="loc_us-gaapArrangementsAndNonarrangementTransactionsMember_10" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xbrldt:contextElement="segment" xlink:from="loc_us-gaapTypeOfArrangementAxis" xlink:to="loc_us-gaapArrangementsAndNonarrangementTransactionsMember_10" xlink:type="arc" order="30" />
      <link:loc xlink:type="locator" xlink:href="gnta-20241231.xsd#GNTA_ConsultancyAgreementsMember" xlink:label="loc_GNTAConsultancyAgreementsMember_90" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapArrangementsAndNonarrangementTransactionsMember" xlink:to="loc_GNTAConsultancyAgreementsMember_90" xlink:type="arc" order="91" />
      <link:loc xlink:type="locator" xlink:href="gnta-20241231.xsd#GNTA_AmendedAndRestatedOSRLicenseAgreementMember" xlink:label="loc_GNTAAmendedAndRestatedOSRLicenseAgreementMember_490" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapArrangementsAndNonarrangementTransactionsMember" xlink:to="loc_GNTAAmendedAndRestatedOSRLicenseAgreementMember_490" xlink:type="arc" order="491" />
      <link:loc xlink:type="locator" xlink:href="gnta-20241231.xsd#GNTA_SublicenseAgreementMember" xlink:label="loc_GNTASublicenseAgreementMember_500" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapArrangementsAndNonarrangementTransactionsMember" xlink:to="loc_GNTASublicenseAgreementMember_500" xlink:type="arc" order="501" />
      <link:loc xlink:type="locator" xlink:href="gnta-20241231.xsd#GNTA_AmendmentToOSRAmendedandRestatedLicenseAgreementMember" xlink:label="loc_GNTAAmendmentToOSRAmendedandRestatedLicenseAgreementMember_510" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapArrangementsAndNonarrangementTransactionsMember" xlink:to="loc_GNTAAmendmentToOSRAmendedandRestatedLicenseAgreementMember_510" xlink:type="arc" order="511" />
      <link:loc xlink:type="locator" xlink:href="gnta-20241231.xsd#GNTA_OSRSponsorResearchAgreementMember" xlink:label="loc_GNTAOSRSponsorResearchAgreementMember_540" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapArrangementsAndNonarrangementTransactionsMember" xlink:to="loc_GNTAOSRSponsorResearchAgreementMember_540" xlink:type="arc" order="541" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_TitleOfIndividualAxis" xlink:label="loc_srtTitleOfIndividualAxis" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaapStatementTable" xlink:to="loc_srtTitleOfIndividualAxis" xlink:type="arc" order="3" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_TitleOfIndividualWithRelationshipToEntityDomain" xlink:label="loc_srtTitleOfIndividualWithRelationshipToEntityDomain" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srtTitleOfIndividualAxis" xlink:to="loc_srtTitleOfIndividualWithRelationshipToEntityDomain" xlink:type="arc" order="20" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_TitleOfIndividualWithRelationshipToEntityDomain" xlink:label="loc_srtTitleOfIndividualWithRelationshipToEntityDomain_10" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xbrldt:contextElement="segment" xlink:from="loc_srtTitleOfIndividualAxis" xlink:to="loc_srtTitleOfIndividualWithRelationshipToEntityDomain_10" xlink:type="arc" order="30" />
      <link:loc xlink:type="locator" xlink:href="gnta-20241231.xsd#GNTA_PierluigiParacchiMember" xlink:label="loc_GNTAPierluigiParacchiMember_100" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srtTitleOfIndividualWithRelationshipToEntityDomain" xlink:to="loc_GNTAPierluigiParacchiMember_100" xlink:type="arc" order="101" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_DirectorMember" xlink:label="loc_srtDirectorMember_110" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srtTitleOfIndividualWithRelationshipToEntityDomain" xlink:to="loc_srtDirectorMember_110" xlink:type="arc" order="111" />
      <link:loc xlink:type="locator" xlink:href="gnta-20241231.xsd#GNTA_NaldiniMember" xlink:label="loc_GNTANaldiniMember_210" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srtTitleOfIndividualWithRelationshipToEntityDomain" xlink:to="loc_GNTANaldiniMember_210" xlink:type="arc" order="211" />
      <link:loc xlink:type="locator" xlink:href="gnta-20241231.xsd#GNTA_Dr.GentnerMember" xlink:label="loc_GNTADr.GentnerMember_230" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srtTitleOfIndividualWithRelationshipToEntityDomain" xlink:to="loc_GNTADr.GentnerMember_230" xlink:type="arc" order="231" />
      <link:loc xlink:type="locator" xlink:href="gnta-20241231.xsd#GNTA_XDGBiomedLLCMember" xlink:label="loc_GNTAXDGBiomedLLCMember_260" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srtTitleOfIndividualWithRelationshipToEntityDomain" xlink:to="loc_GNTAXDGBiomedLLCMember_260" xlink:type="arc" order="261" />
      <link:loc xlink:type="locator" xlink:href="gnta-20241231.xsd#GNTA_Mr.RussoMember" xlink:label="loc_GNTAMr.RussoMember_280" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srtTitleOfIndividualWithRelationshipToEntityDomain" xlink:to="loc_GNTAMr.RussoMember_280" xlink:type="arc" order="281" />
      <link:loc xlink:type="locator" xlink:href="gnta-20241231.xsd#GNTA_RichardSlanskyMember" xlink:label="loc_GNTARichardSlanskyMember_350" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srtTitleOfIndividualWithRelationshipToEntityDomain" xlink:to="loc_GNTARichardSlanskyMember_350" xlink:type="arc" order="351" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RelatedPartyTransactionsByRelatedPartyAxis" xlink:label="loc_us-gaapRelatedPartyTransactionsByRelatedPartyAxis" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaapStatementTable" xlink:to="loc_us-gaapRelatedPartyTransactionsByRelatedPartyAxis" xlink:type="arc" order="4" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RelatedPartyDomain" xlink:label="loc_us-gaapRelatedPartyDomain" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaapRelatedPartyTransactionsByRelatedPartyAxis" xlink:to="loc_us-gaapRelatedPartyDomain" xlink:type="arc" order="20" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RelatedPartyDomain" xlink:label="loc_us-gaapRelatedPartyDomain_10" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xbrldt:contextElement="segment" xlink:from="loc_us-gaapRelatedPartyTransactionsByRelatedPartyAxis" xlink:to="loc_us-gaapRelatedPartyDomain_10" xlink:type="arc" order="30" />
      <link:loc xlink:type="locator" xlink:href="gnta-20241231.xsd#GNTA_PierluigiParacchiMember" xlink:label="loc_GNTAPierluigiParacchiMember_110" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapRelatedPartyDomain" xlink:to="loc_GNTAPierluigiParacchiMember_110" xlink:type="arc" order="112" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RelatedPartyMember" xlink:label="loc_us-gaapRelatedPartyMember_280" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapRelatedPartyDomain" xlink:to="loc_us-gaapRelatedPartyMember_280" xlink:type="arc" order="282" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_ProductOrServiceAxis" xlink:label="loc_srtProductOrServiceAxis" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaapStatementTable" xlink:to="loc_srtProductOrServiceAxis" xlink:type="arc" order="5" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_ProductsAndServicesDomain" xlink:label="loc_srtProductsAndServicesDomain" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srtProductOrServiceAxis" xlink:to="loc_srtProductsAndServicesDomain" xlink:type="arc" order="20" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_ProductsAndServicesDomain" xlink:label="loc_srtProductsAndServicesDomain_10" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xbrldt:contextElement="segment" xlink:from="loc_srtProductOrServiceAxis" xlink:to="loc_srtProductsAndServicesDomain_10" xlink:type="arc" order="30" />
      <link:loc xlink:type="locator" xlink:href="gnta-20241231.xsd#GNTA_ConsultancyMember" xlink:label="loc_GNTAConsultancyMember_250" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srtProductsAndServicesDomain" xlink:to="loc_GNTAConsultancyMember_250" xlink:type="arc" order="252" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_StatementScenarioAxis" xlink:label="loc_srtStatementScenarioAxis" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaapStatementTable" xlink:to="loc_srtStatementScenarioAxis" xlink:type="arc" order="6" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_ScenarioUnspecifiedDomain" xlink:label="loc_srtScenarioUnspecifiedDomain" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srtStatementScenarioAxis" xlink:to="loc_srtScenarioUnspecifiedDomain" xlink:type="arc" order="20" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_ScenarioUnspecifiedDomain" xlink:label="loc_srtScenarioUnspecifiedDomain_10" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xbrldt:contextElement="segment" xlink:from="loc_srtStatementScenarioAxis" xlink:to="loc_srtScenarioUnspecifiedDomain_10" xlink:type="arc" order="30" />
      <link:loc xlink:type="locator" xlink:href="gnta-20241231.xsd#GNTA_FirstIndicationMember" xlink:label="loc_GNTAFirstIndicationMember_460" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srtScenarioUnspecifiedDomain" xlink:to="loc_GNTAFirstIndicationMember_460" xlink:type="arc" order="461" />
      <link:loc xlink:type="locator" xlink:href="gnta-20241231.xsd#GNTA_SecondIndicationMember" xlink:label="loc_GNTASecondIndicationMember_470" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srtScenarioUnspecifiedDomain" xlink:to="loc_GNTASecondIndicationMember_470" xlink:type="arc" order="471" />
      <link:loc xlink:type="locator" xlink:href="gnta-20241231.xsd#GNTA_ThirdIndicationMember" xlink:label="loc_GNTAThirdIndicationMember_480" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srtScenarioUnspecifiedDomain" xlink:to="loc_GNTAThirdIndicationMember_480" xlink:type="arc" order="481" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AwardTypeAxis" xlink:label="loc_us-gaapAwardTypeAxis" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaapStatementTable" xlink:to="loc_us-gaapAwardTypeAxis" xlink:type="arc" order="7" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:label="loc_us-gaapShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaapAwardTypeAxis" xlink:to="loc_us-gaapShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:type="arc" order="20" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:label="loc_us-gaapShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_10" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xbrldt:contextElement="segment" xlink:from="loc_us-gaapAwardTypeAxis" xlink:to="loc_us-gaapShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_10" xlink:type="arc" order="30" />
      <link:loc xlink:type="locator" xlink:href="gnta-20241231.xsd#GNTA_FirstSolidCancerIndicationOptionFeeMember" xlink:label="loc_GNTAFirstSolidCancerIndicationOptionFeeMember_510" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:to="loc_GNTAFirstSolidCancerIndicationOptionFeeMember_510" xlink:type="arc" order="512" />
      <link:loc xlink:type="locator" xlink:href="gnta-20241231.xsd#GNTA_SecondSolidCancerIndicationOptionFeeMember" xlink:label="loc_GNTASecondSolidCancerIndicationOptionFeeMember_520" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:to="loc_GNTASecondSolidCancerIndicationOptionFeeMember_520" xlink:type="arc" order="522" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ResearchAndDevelopmentExpense" xlink:label="loc_us-gaapResearchAndDevelopmentExpense_560" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapStatementLineItems" xlink:to="loc_us-gaapResearchAndDevelopmentExpense_560" xlink:type="arc" order="0" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DeferredTaxAssetsTaxCreditCarryforwardsResearch" xlink:label="loc_us-gaapDeferredTaxAssetsTaxCreditCarryforwardsResearch_560" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapStatementLineItems" xlink:to="loc_us-gaapDeferredTaxAssetsTaxCreditCarryforwardsResearch_560" xlink:type="arc" order="1" />
      <link:loc xlink:type="locator" xlink:href="gnta-20241231.xsd#GNTA_IncreaseDecreaseInResearchAndDevelopmentExpense" xlink:label="loc_GNTAIncreaseDecreaseInResearchAndDevelopmentExpense_560" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapStatementLineItems" xlink:to="loc_GNTAIncreaseDecreaseInResearchAndDevelopmentExpense_560" xlink:type="arc" order="2" />
      <link:loc xlink:type="locator" xlink:href="gnta-20241231.xsd#GNTA_ResearchAndDevelopmentTaxCreditsPercentage" xlink:label="loc_GNTAResearchAndDevelopmentTaxCreditsPercentage_560" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapStatementLineItems" xlink:to="loc_GNTAResearchAndDevelopmentTaxCreditsPercentage_560" xlink:type="arc" order="3" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_GeneralAndAdministrativeExpense" xlink:label="loc_us-gaapGeneralAndAdministrativeExpense_560" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapStatementLineItems" xlink:to="loc_us-gaapGeneralAndAdministrativeExpense_560" xlink:type="arc" order="4" />
      <link:loc xlink:type="locator" xlink:href="gnta-20241231.xsd#GNTA_DecreaseInGeneralAndAdministrativeExpenses" xlink:label="loc_GNTADecreaseInGeneralAndAdministrativeExpenses_560" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapStatementLineItems" xlink:to="loc_GNTADecreaseInGeneralAndAdministrativeExpenses_560" xlink:type="arc" order="5" />
      <link:loc xlink:type="locator" xlink:href="gnta-20241231.xsd#GNTA_DecreaseInAccountingLegalAndOtherProfessional" xlink:label="loc_GNTADecreaseInAccountingLegalAndOtherProfessional_560" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapStatementLineItems" xlink:to="loc_GNTADecreaseInAccountingLegalAndOtherProfessional_560" xlink:type="arc" order="6" />
      <link:loc xlink:type="locator" xlink:href="gnta-20241231.xsd#GNTA_DecreaseInAuditExpenses" xlink:label="loc_GNTADecreaseInAuditExpenses_560" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapStatementLineItems" xlink:to="loc_GNTADecreaseInAuditExpenses_560" xlink:type="arc" order="7" />
      <link:loc xlink:type="locator" xlink:href="gnta-20241231.xsd#GNTA_IncreaseInLegalFees" xlink:label="loc_GNTAIncreaseInLegalFees_560" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapStatementLineItems" xlink:to="loc_GNTAIncreaseInLegalFees_560" xlink:type="arc" order="8" />
      <link:loc xlink:type="locator" xlink:href="gnta-20241231.xsd#GNTA_DecreaseInOtherMinorCosts" xlink:label="loc_GNTADecreaseInOtherMinorCosts_560" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapStatementLineItems" xlink:to="loc_GNTADecreaseInOtherMinorCosts_560" xlink:type="arc" order="9" />
      <link:loc xlink:type="locator" xlink:href="gnta-20241231.xsd#GNTA_IncreaseInCommunicationAndItRelatedCosts" xlink:label="loc_GNTAIncreaseInCommunicationAndItRelatedCosts_560" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapStatementLineItems" xlink:to="loc_GNTAIncreaseInCommunicationAndItRelatedCosts_560" xlink:type="arc" order="10" />
      <link:loc xlink:type="locator" xlink:href="gnta-20241231.xsd#GNTA_DecreaseInConsultantsAndOtherThirdPartyCosts" xlink:label="loc_GNTADecreaseInConsultantsAndOtherThirdPartyCosts_560" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapStatementLineItems" xlink:to="loc_GNTADecreaseInConsultantsAndOtherThirdPartyCosts_560" xlink:type="arc" order="11" />
      <link:loc xlink:type="locator" xlink:href="gnta-20241231.xsd#GNTA_ConsultantExpense" xlink:label="loc_GNTAConsultantExpense_560" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapStatementLineItems" xlink:to="loc_GNTAConsultantExpense_560" xlink:type="arc" order="12" />
      <link:loc xlink:type="locator" xlink:href="gnta-20241231.xsd#GNTA_DecreaseInOtherGeneralAndAdministrativeCosts" xlink:label="loc_GNTADecreaseInOtherGeneralAndAdministrativeCosts_560" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapStatementLineItems" xlink:to="loc_GNTADecreaseInOtherGeneralAndAdministrativeCosts_560" xlink:type="arc" order="13" />
      <link:loc xlink:type="locator" xlink:href="gnta-20241231.xsd#GNTA_DecreaseInLimitedLiabilityInsuranceCost" xlink:label="loc_GNTADecreaseInLimitedLiabilityInsuranceCost_560" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapStatementLineItems" xlink:to="loc_GNTADecreaseInLimitedLiabilityInsuranceCost_560" xlink:type="arc" order="14" />
      <link:loc xlink:type="locator" xlink:href="gnta-20241231.xsd#GNTA_IncreaseInPatentMaintenanceCosts" xlink:label="loc_GNTAIncreaseInPatentMaintenanceCosts_560" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapStatementLineItems" xlink:to="loc_GNTAIncreaseInPatentMaintenanceCosts_560" xlink:type="arc" order="15" />
      <link:loc xlink:type="locator" xlink:href="gnta-20241231.xsd#GNTA_OtherCumulativeChange" xlink:label="loc_GNTAOtherCumulativeChange_560" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapStatementLineItems" xlink:to="loc_GNTAOtherCumulativeChange_560" xlink:type="arc" order="16" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SalariesWagesAndOfficersCompensation" xlink:label="loc_us-gaapSalariesWagesAndOfficersCompensation_560" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapStatementLineItems" xlink:to="loc_us-gaapSalariesWagesAndOfficersCompensation_560" xlink:type="arc" order="17" />
      <link:loc xlink:type="locator" xlink:href="gnta-20241231.xsd#GNTA_PercentageOfAnnualBonus" xlink:label="loc_GNTAPercentageOfAnnualBonus_560" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapStatementLineItems" xlink:to="loc_GNTAPercentageOfAnnualBonus_560" xlink:type="arc" order="18" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_EmployeeBenefitsAndShareBasedCompensation" xlink:label="loc_us-gaapEmployeeBenefitsAndShareBasedCompensation_560" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapStatementLineItems" xlink:to="loc_us-gaapEmployeeBenefitsAndShareBasedCompensation_560" xlink:type="arc" order="19" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedNumberOfShares" xlink:label="loc_us-gaapSharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedNumberOfShares_560" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapStatementLineItems" xlink:to="loc_us-gaapSharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedNumberOfShares_560" xlink:type="arc" order="20" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AccruedBonusesCurrent" xlink:label="loc_us-gaapAccruedBonusesCurrent_560" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapStatementLineItems" xlink:to="loc_us-gaapAccruedBonusesCurrent_560" xlink:type="arc" order="21" />
      <link:loc xlink:type="locator" xlink:href="gnta-20241231.xsd#GNTA_BonusOutstandingPaid" xlink:label="loc_GNTABonusOutstandingPaid_560" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapStatementLineItems" xlink:to="loc_GNTABonusOutstandingPaid_560" xlink:type="arc" order="22" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AccruedBonusesCurrentAndNoncurrent" xlink:label="loc_us-gaapAccruedBonusesCurrentAndNoncurrent_560" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapStatementLineItems" xlink:to="loc_us-gaapAccruedBonusesCurrentAndNoncurrent_560" xlink:type="arc" order="23" />
      <link:loc xlink:type="locator" xlink:href="gnta-20241231.xsd#GNTA_AnnualFee" xlink:label="loc_GNTAAnnualFee_560" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapStatementLineItems" xlink:to="loc_GNTAAnnualFee_560" xlink:type="arc" order="24" />
      <link:loc xlink:type="locator" xlink:href="gnta-20241231.xsd#GNTA_RecurringFees" xlink:label="loc_GNTARecurringFees_560" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapStatementLineItems" xlink:to="loc_GNTARecurringFees_560" xlink:type="arc" order="25" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_EmployeeRelatedLiabilitiesCurrentAndNoncurrent" xlink:label="loc_us-gaapEmployeeRelatedLiabilitiesCurrentAndNoncurrent_560" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapStatementLineItems" xlink:to="loc_us-gaapEmployeeRelatedLiabilitiesCurrentAndNoncurrent_560" xlink:type="arc" order="26" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SalariesAndWages" xlink:label="loc_us-gaapSalariesAndWages_560" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapStatementLineItems" xlink:to="loc_us-gaapSalariesAndWages_560" xlink:type="arc" order="27" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AllocatedShareBasedCompensationExpense" xlink:label="loc_us-gaapAllocatedShareBasedCompensationExpense_560" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapStatementLineItems" xlink:to="loc_us-gaapAllocatedShareBasedCompensationExpense_560" xlink:type="arc" order="28" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DeferredCompensationArrangementWithIndividualCompensationExpense" xlink:label="loc_us-gaapDeferredCompensationArrangementWithIndividualCompensationExpense_560" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapStatementLineItems" xlink:to="loc_us-gaapDeferredCompensationArrangementWithIndividualCompensationExpense_560" xlink:type="arc" order="29" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_OtherComprehensiveIncomeLossTax" xlink:label="loc_us-gaapOtherComprehensiveIncomeLossTax_560" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapStatementLineItems" xlink:to="loc_us-gaapOtherComprehensiveIncomeLossTax_560" xlink:type="arc" order="30" />
      <link:loc xlink:type="locator" xlink:href="gnta-20241231.xsd#GNTA_FutureOptionFees" xlink:label="loc_GNTAFutureOptionFees_560" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapStatementLineItems" xlink:to="loc_GNTAFutureOptionFees_560" xlink:type="arc" order="31" />
      <link:loc xlink:type="locator" xlink:href="gnta-20241231.xsd#GNTA_UpfrontFee" xlink:label="loc_GNTAUpfrontFee_560" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapStatementLineItems" xlink:to="loc_GNTAUpfrontFee_560" xlink:type="arc" order="32" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_TaxesAndLicenses" xlink:label="loc_us-gaapTaxesAndLicenses_560" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapStatementLineItems" xlink:to="loc_us-gaapTaxesAndLicenses_560" xlink:type="arc" order="33" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_OtherCommitmentsDescription" xlink:label="loc_us-gaapOtherCommitmentsDescription_560" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapStatementLineItems" xlink:to="loc_us-gaapOtherCommitmentsDescription_560" xlink:type="arc" order="34" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_OperatingCostsAndExpenses" xlink:label="loc_us-gaapOperatingCostsAndExpenses_560" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapStatementLineItems" xlink:to="loc_us-gaapOperatingCostsAndExpenses_560" xlink:type="arc" order="35" />
      <link:loc xlink:type="locator" xlink:href="gnta-20241231.xsd#GNTA_OptionFee" xlink:label="loc_GNTAOptionFee_560" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapStatementLineItems" xlink:to="loc_GNTAOptionFee_560" xlink:type="arc" order="36" />
      <link:loc xlink:type="locator" xlink:href="gnta-20241231.xsd#GNTA_AgreementFee" xlink:label="loc_GNTAAgreementFee_560" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapStatementLineItems" xlink:to="loc_GNTAAgreementFee_560" xlink:type="arc" order="37" />
      <link:loc xlink:type="locator" xlink:href="gnta-20241231.xsd#GNTA_TotalProjectCashConsideration" xlink:label="loc_GNTATotalProjectCashConsideration_560" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapStatementLineItems" xlink:to="loc_GNTATotalProjectCashConsideration_560" xlink:type="arc" order="38" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PaymentsToAcquireInProcessResearchAndDevelopment" xlink:label="loc_us-gaapPaymentsToAcquireInProcessResearchAndDevelopment_560" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapStatementLineItems" xlink:to="loc_us-gaapPaymentsToAcquireInProcessResearchAndDevelopment_560" xlink:type="arc" order="39" />
    </link:definitionLink>
    <link:definitionLink xlink:type="extended" xlink:role="http://genenta.com/role/ScheduleOfCompanyObligationsByContractualMaturityDetails" xlink:title="999067 - Disclosure - Schedule of company obligations by contractual maturity (Details)">
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CollaborativeArrangementsAndNoncollaborativeArrangementTransactionsLineItems" xlink:label="loc_us-gaapCollaborativeArrangementsAndNoncollaborativeArrangementTransactionsLineItems" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfCollaborativeArrangementsAndNoncollaborativeArrangementTransactionsTable" xlink:label="loc_us-gaapScheduleOfCollaborativeArrangementsAndNoncollaborativeArrangementTransactionsTable" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xbrldt:contextElement="segment" xlink:from="loc_us-gaapCollaborativeArrangementsAndNoncollaborativeArrangementTransactionsLineItems" xlink:to="loc_us-gaapScheduleOfCollaborativeArrangementsAndNoncollaborativeArrangementTransactionsTable" xlink:type="arc" order="10" xbrldt:closed="true" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_TypeOfArrangementAxis" xlink:label="loc_us-gaapTypeOfArrangementAxis" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaapScheduleOfCollaborativeArrangementsAndNoncollaborativeArrangementTransactionsTable" xlink:to="loc_us-gaapTypeOfArrangementAxis" xlink:type="arc" order="1" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ArrangementsAndNonarrangementTransactionsMember" xlink:label="loc_us-gaapArrangementsAndNonarrangementTransactionsMember" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaapTypeOfArrangementAxis" xlink:to="loc_us-gaapArrangementsAndNonarrangementTransactionsMember" xlink:type="arc" order="20" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ArrangementsAndNonarrangementTransactionsMember" xlink:label="loc_us-gaapArrangementsAndNonarrangementTransactionsMember_10" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xbrldt:contextElement="segment" xlink:from="loc_us-gaapTypeOfArrangementAxis" xlink:to="loc_us-gaapArrangementsAndNonarrangementTransactionsMember_10" xlink:type="arc" order="30" />
      <link:loc xlink:type="locator" xlink:href="gnta-20241231.xsd#GNTA_OSRMember" xlink:label="loc_GNTAOSRMember_0" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapArrangementsAndNonarrangementTransactionsMember" xlink:to="loc_GNTAOSRMember_0" xlink:type="arc" order="1" />
      <link:loc xlink:type="locator" xlink:href="gnta-20241231.xsd#GNTA_OSROperatingLeasesAndOfficeRentMember" xlink:label="loc_GNTAOSROperatingLeasesAndOfficeRentMember_10" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapArrangementsAndNonarrangementTransactionsMember" xlink:to="loc_GNTAOSROperatingLeasesAndOfficeRentMember_10" xlink:type="arc" order="11" />
      <link:loc xlink:type="locator" xlink:href="gnta-20241231.xsd#GNTA_OSRSponsorResearchAgreementAndAmendedaAndRestatedLicensetAgreementMember" xlink:label="loc_GNTAOSRSponsorResearchAgreementAndAmendedaAndRestatedLicensetAgreementMember_20" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapArrangementsAndNonarrangementTransactionsMember" xlink:to="loc_GNTAOSRSponsorResearchAgreementAndAmendedaAndRestatedLicensetAgreementMember_20" xlink:type="arc" order="21" />
      <link:loc xlink:type="locator" xlink:href="gnta-20241231.xsd#GNTA_AGCManufacturingMember" xlink:label="loc_GNTAAGCManufacturingMember_30" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapArrangementsAndNonarrangementTransactionsMember" xlink:to="loc_GNTAAGCManufacturingMember_30" xlink:type="arc" order="31" />
      <link:loc xlink:type="locator" xlink:href="gnta-20241231.xsd#GNTA_InsurancePolicyMember" xlink:label="loc_GNTAInsurancePolicyMember_40" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapArrangementsAndNonarrangementTransactionsMember" xlink:to="loc_GNTAInsurancePolicyMember_40" xlink:type="arc" order="41" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ContractualObligation" xlink:label="loc_us-gaapContractualObligation_70" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapCollaborativeArrangementsAndNoncollaborativeArrangementTransactionsLineItems" xlink:to="loc_us-gaapContractualObligation_70" xlink:type="arc" order="0" />
      <link:loc xlink:type="locator" xlink:href="gnta-20241231.xsd#GNTA_ContractualObligationDueInPaymentsByPeriodLessThanYear" xlink:label="loc_GNTAContractualObligationDueInPaymentsByPeriodLessThanYear_70" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapCollaborativeArrangementsAndNoncollaborativeArrangementTransactionsLineItems" xlink:to="loc_GNTAContractualObligationDueInPaymentsByPeriodLessThanYear_70" xlink:type="arc" order="1" />
      <link:loc xlink:type="locator" xlink:href="gnta-20241231.xsd#GNTA_ContractualObligationDueInOneToThirdYear" xlink:label="loc_GNTAContractualObligationDueInOneToThirdYear_70" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapCollaborativeArrangementsAndNoncollaborativeArrangementTransactionsLineItems" xlink:to="loc_GNTAContractualObligationDueInOneToThirdYear_70" xlink:type="arc" order="2" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ContractualObligationDueInFourthAndFifthYear" xlink:label="loc_us-gaapContractualObligationDueInFourthAndFifthYear_70" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapCollaborativeArrangementsAndNoncollaborativeArrangementTransactionsLineItems" xlink:to="loc_us-gaapContractualObligationDueInFourthAndFifthYear_70" xlink:type="arc" order="3" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ContractualObligationDueAfterFifthYear" xlink:label="loc_us-gaapContractualObligationDueAfterFifthYear_70" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapCollaborativeArrangementsAndNoncollaborativeArrangementTransactionsLineItems" xlink:to="loc_us-gaapContractualObligationDueAfterFifthYear_70" xlink:type="arc" order="4" />
    </link:definitionLink>
    <link:definitionLink xlink:type="extended" xlink:role="http://genenta.com/role/CommitmentsAndContingenciesDetailsNarrative" xlink:title="999068 - Disclosure - Commitments and contingencies (Details Narrative)">
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LossContingenciesLineItems" xlink:label="loc_us-gaapLossContingenciesLineItems" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LossContingenciesTable" xlink:label="loc_us-gaapLossContingenciesTable" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xbrldt:contextElement="segment" xlink:from="loc_us-gaapLossContingenciesLineItems" xlink:to="loc_us-gaapLossContingenciesTable" xlink:type="arc" order="10" xbrldt:closed="true" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_TypeOfArrangementAxis" xlink:label="loc_us-gaapTypeOfArrangementAxis" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaapLossContingenciesTable" xlink:to="loc_us-gaapTypeOfArrangementAxis" xlink:type="arc" order="1" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ArrangementsAndNonarrangementTransactionsMember" xlink:label="loc_us-gaapArrangementsAndNonarrangementTransactionsMember" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaapTypeOfArrangementAxis" xlink:to="loc_us-gaapArrangementsAndNonarrangementTransactionsMember" xlink:type="arc" order="20" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ArrangementsAndNonarrangementTransactionsMember" xlink:label="loc_us-gaapArrangementsAndNonarrangementTransactionsMember_10" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xbrldt:contextElement="segment" xlink:from="loc_us-gaapTypeOfArrangementAxis" xlink:to="loc_us-gaapArrangementsAndNonarrangementTransactionsMember_10" xlink:type="arc" order="30" />
      <link:loc xlink:type="locator" xlink:href="gnta-20241231.xsd#GNTA_OriginalOSRLicenseAgreementMember" xlink:label="loc_GNTAOriginalOSRLicenseAgreementMember_0" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapArrangementsAndNonarrangementTransactionsMember" xlink:to="loc_GNTAOriginalOSRLicenseAgreementMember_0" xlink:type="arc" order="1" />
      <link:loc xlink:type="locator" xlink:href="gnta-20241231.xsd#GNTA_AGCBiologicsAgreementMember" xlink:label="loc_GNTAAGCBiologicsAgreementMember_60" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapArrangementsAndNonarrangementTransactionsMember" xlink:to="loc_GNTAAGCBiologicsAgreementMember_60" xlink:type="arc" order="61" />
      <link:loc xlink:type="locator" xlink:href="gnta-20241231.xsd#GNTA_AGCAgreementMember" xlink:label="loc_GNTAAGCAgreementMember_90" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapArrangementsAndNonarrangementTransactionsMember" xlink:to="loc_GNTAAGCAgreementMember_90" xlink:type="arc" order="91" />
      <link:loc xlink:type="locator" xlink:href="gnta-20241231.xsd#GNTA_LVVBatchMember" xlink:label="loc_GNTALVVBatchMember_100" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapArrangementsAndNonarrangementTransactionsMember" xlink:to="loc_GNTALVVBatchMember_100" xlink:type="arc" order="101" />
      <link:loc xlink:type="locator" xlink:href="gnta-20241231.xsd#GNTA_ProcessTransferAgreementMember" xlink:label="loc_GNTAProcessTransferAgreementMember_110" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapArrangementsAndNonarrangementTransactionsMember" xlink:to="loc_GNTAProcessTransferAgreementMember_110" xlink:type="arc" order="111" />
      <link:loc xlink:type="locator" xlink:href="gnta-20241231.xsd#GNTA_ManufacturingServiceAgreementMember" xlink:label="loc_GNTAManufacturingServiceAgreementMember_140" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapArrangementsAndNonarrangementTransactionsMember" xlink:to="loc_GNTAManufacturingServiceAgreementMember_140" xlink:type="arc" order="141" />
      <link:loc xlink:type="locator" xlink:href="gnta-20241231.xsd#GNTA_MasterServiceAgreementMember" xlink:label="loc_GNTAMasterServiceAgreementMember_160" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapArrangementsAndNonarrangementTransactionsMember" xlink:to="loc_GNTAMasterServiceAgreementMember_160" xlink:type="arc" order="161" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RelatedPartyTransactionAxis" xlink:label="loc_us-gaapRelatedPartyTransactionAxis" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaapLossContingenciesTable" xlink:to="loc_us-gaapRelatedPartyTransactionAxis" xlink:type="arc" order="2" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RelatedPartyTransactionDomain" xlink:label="loc_us-gaapRelatedPartyTransactionDomain" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaapRelatedPartyTransactionAxis" xlink:to="loc_us-gaapRelatedPartyTransactionDomain" xlink:type="arc" order="20" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RelatedPartyTransactionDomain" xlink:label="loc_us-gaapRelatedPartyTransactionDomain_10" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xbrldt:contextElement="segment" xlink:from="loc_us-gaapRelatedPartyTransactionAxis" xlink:to="loc_us-gaapRelatedPartyTransactionDomain_10" xlink:type="arc" order="30" />
      <link:loc xlink:type="locator" xlink:href="gnta-20241231.xsd#GNTA_SanRaffaeleHospitalMember" xlink:label="loc_GNTASanRaffaeleHospitalMember_20" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapRelatedPartyTransactionDomain" xlink:to="loc_GNTASanRaffaeleHospitalMember_20" xlink:type="arc" order="21" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_LegalEntityAxis" xlink:label="loc_deiLegalEntityAxis" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaapLossContingenciesTable" xlink:to="loc_deiLegalEntityAxis" xlink:type="arc" order="3" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_EntityDomain" xlink:label="loc_deiEntityDomain" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_deiLegalEntityAxis" xlink:to="loc_deiEntityDomain" xlink:type="arc" order="20" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_EntityDomain" xlink:label="loc_deiEntityDomain_10" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xbrldt:contextElement="segment" xlink:from="loc_deiLegalEntityAxis" xlink:to="loc_deiEntityDomain_10" xlink:type="arc" order="30" />
      <link:loc xlink:type="locator" xlink:href="gnta-20241231.xsd#GNTA_OSRMember" xlink:label="loc_GNTAOSRMember_50" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_deiEntityDomain" xlink:to="loc_GNTAOSRMember_50" xlink:type="arc" order="51" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_RangeAxis" xlink:label="loc_srtRangeAxis" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaapLossContingenciesTable" xlink:to="loc_srtRangeAxis" xlink:type="arc" order="4" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_RangeMember" xlink:label="loc_srtRangeMember" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srtRangeAxis" xlink:to="loc_srtRangeMember" xlink:type="arc" order="20" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_RangeMember" xlink:label="loc_srtRangeMember_10" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xbrldt:contextElement="segment" xlink:from="loc_srtRangeAxis" xlink:to="loc_srtRangeMember_10" xlink:type="arc" order="30" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_MinimumMember" xlink:label="loc_srtMinimumMember_70" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srtRangeMember" xlink:to="loc_srtMinimumMember_70" xlink:type="arc" order="71" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_MaximumMember" xlink:label="loc_srtMaximumMember_80" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srtRangeMember" xlink:to="loc_srtMaximumMember_80" xlink:type="arc" order="81" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_OtherCommitmentsDescription" xlink:label="loc_us-gaapOtherCommitmentsDescription_200" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapLossContingenciesLineItems" xlink:to="loc_us-gaapOtherCommitmentsDescription_200" xlink:type="arc" order="0" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InvestmentOwnedBalancePrincipalAmount" xlink:label="loc_us-gaapInvestmentOwnedBalancePrincipalAmount_200" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapLossContingenciesLineItems" xlink:to="loc_us-gaapInvestmentOwnedBalancePrincipalAmount_200" xlink:type="arc" order="1" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CostsAndExpensesRelatedParty" xlink:label="loc_us-gaapCostsAndExpensesRelatedParty_200" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapLossContingenciesLineItems" xlink:to="loc_us-gaapCostsAndExpensesRelatedParty_200" xlink:type="arc" order="2" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ManufacturingCosts" xlink:label="loc_us-gaapManufacturingCosts_200" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapLossContingenciesLineItems" xlink:to="loc_us-gaapManufacturingCosts_200" xlink:type="arc" order="3" />
      <link:loc xlink:type="locator" xlink:href="gnta-20241231.xsd#GNTA_PercentageOfRoyalties" xlink:label="loc_GNTAPercentageOfRoyalties_200" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapLossContingenciesLineItems" xlink:to="loc_GNTAPercentageOfRoyalties_200" xlink:type="arc" order="4" />
      <link:loc xlink:type="locator" xlink:href="gnta-20241231.xsd#GNTA_PotentialMilestone" xlink:label="loc_GNTAPotentialMilestone_200" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapLossContingenciesLineItems" xlink:to="loc_GNTAPotentialMilestone_200" xlink:type="arc" order="5" />
      <link:loc xlink:type="locator" xlink:href="gnta-20241231.xsd#GNTA_RoyaltyFeePercentage" xlink:label="loc_GNTARoyaltyFeePercentage_200" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapLossContingenciesLineItems" xlink:to="loc_GNTARoyaltyFeePercentage_200" xlink:type="arc" order="6" />
      <link:loc xlink:type="locator" xlink:href="gnta-20241231.xsd#GNTA_TechnologyTransferFee" xlink:label="loc_GNTATechnologyTransferFee_200" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapLossContingenciesLineItems" xlink:to="loc_GNTATechnologyTransferFee_200" xlink:type="arc" order="7" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AdvancesOnInventoryPurchases" xlink:label="loc_us-gaapAdvancesOnInventoryPurchases_200" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapLossContingenciesLineItems" xlink:to="loc_us-gaapAdvancesOnInventoryPurchases_200" xlink:type="arc" order="8" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_OtherInventorySupplies" xlink:label="loc_us-gaapOtherInventorySupplies_200" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapLossContingenciesLineItems" xlink:to="loc_us-gaapOtherInventorySupplies_200" xlink:type="arc" order="9" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InventoryRawMaterials" xlink:label="loc_us-gaapInventoryRawMaterials_200" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapLossContingenciesLineItems" xlink:to="loc_us-gaapInventoryRawMaterials_200" xlink:type="arc" order="10" />
      <link:loc xlink:type="locator" xlink:href="gnta-20241231.xsd#GNTA_CancellationFeesPercentage" xlink:label="loc_GNTACancellationFeesPercentage_200" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapLossContingenciesLineItems" xlink:to="loc_GNTACancellationFeesPercentage_200" xlink:type="arc" order="11" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CostDirectMaterial" xlink:label="loc_us-gaapCostDirectMaterial_200" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapLossContingenciesLineItems" xlink:to="loc_us-gaapCostDirectMaterial_200" xlink:type="arc" order="12" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ProductionCosts" xlink:label="loc_us-gaapProductionCosts_200" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapLossContingenciesLineItems" xlink:to="loc_us-gaapProductionCosts_200" xlink:type="arc" order="13" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PaymentsForRent" xlink:label="loc_us-gaapPaymentsForRent_200" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapLossContingenciesLineItems" xlink:to="loc_us-gaapPaymentsForRent_200" xlink:type="arc" order="14" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LeaseCost" xlink:label="loc_us-gaapLeaseCost_200" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapLossContingenciesLineItems" xlink:to="loc_us-gaapLeaseCost_200" xlink:type="arc" order="15" />
    </link:definitionLink>
    <link:definitionLink xlink:type="extended" xlink:role="http://genenta.com/role/SubsequentEventsDetailsNarrative" xlink:title="999069 - Disclosure - Subsequent events (Details Narrative)">
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SubsequentEventLineItems" xlink:label="loc_us-gaapSubsequentEventLineItems" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SubsequentEventTable" xlink:label="loc_us-gaapSubsequentEventTable" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xbrldt:contextElement="segment" xlink:from="loc_us-gaapSubsequentEventLineItems" xlink:to="loc_us-gaapSubsequentEventTable" xlink:type="arc" order="10" xbrldt:closed="true" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_TypeOfArrangementAxis" xlink:label="loc_us-gaapTypeOfArrangementAxis" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaapSubsequentEventTable" xlink:to="loc_us-gaapTypeOfArrangementAxis" xlink:type="arc" order="1" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ArrangementsAndNonarrangementTransactionsMember" xlink:label="loc_us-gaapArrangementsAndNonarrangementTransactionsMember" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaapTypeOfArrangementAxis" xlink:to="loc_us-gaapArrangementsAndNonarrangementTransactionsMember" xlink:type="arc" order="20" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ArrangementsAndNonarrangementTransactionsMember" xlink:label="loc_us-gaapArrangementsAndNonarrangementTransactionsMember_10" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xbrldt:contextElement="segment" xlink:from="loc_us-gaapTypeOfArrangementAxis" xlink:to="loc_us-gaapArrangementsAndNonarrangementTransactionsMember_10" xlink:type="arc" order="30" />
      <link:loc xlink:type="locator" xlink:href="gnta-20241231.xsd#GNTA_AGCBiologicsAgreementMember" xlink:label="loc_GNTAAGCBiologicsAgreementMember_0" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapArrangementsAndNonarrangementTransactionsMember" xlink:to="loc_GNTAAGCBiologicsAgreementMember_0" xlink:type="arc" order="1" />
      <link:loc xlink:type="locator" xlink:href="gnta-20241231.xsd#GNTA_SubscriptionAgreementMember" xlink:label="loc_GNTASubscriptionAgreementMember_10" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapArrangementsAndNonarrangementTransactionsMember" xlink:to="loc_GNTASubscriptionAgreementMember_10" xlink:type="arc" order="11" />
      <link:loc xlink:type="locator" xlink:href="gnta-20241231.xsd#GNTA_PriorSalesAgreementMember" xlink:label="loc_GNTAPriorSalesAgreementMember_120" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapArrangementsAndNonarrangementTransactionsMember" xlink:to="loc_GNTAPriorSalesAgreementMember_120" xlink:type="arc" order="121" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SubsequentEventTypeAxis" xlink:label="loc_us-gaapSubsequentEventTypeAxis" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaapSubsequentEventTable" xlink:to="loc_us-gaapSubsequentEventTypeAxis" xlink:type="arc" order="2" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SubsequentEventTypeDomain" xlink:label="loc_us-gaapSubsequentEventTypeDomain" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaapSubsequentEventTypeAxis" xlink:to="loc_us-gaapSubsequentEventTypeDomain" xlink:type="arc" order="20" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SubsequentEventTypeDomain" xlink:label="loc_us-gaapSubsequentEventTypeDomain_10" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xbrldt:contextElement="segment" xlink:from="loc_us-gaapSubsequentEventTypeAxis" xlink:to="loc_us-gaapSubsequentEventTypeDomain_10" xlink:type="arc" order="30" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SubsequentEventMember" xlink:label="loc_us-gaapSubsequentEventMember_0" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapSubsequentEventTypeDomain" xlink:to="loc_us-gaapSubsequentEventMember_0" xlink:type="arc" order="2" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FinancialInstrumentAxis" xlink:label="loc_us-gaapFinancialInstrumentAxis" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaapSubsequentEventTable" xlink:to="loc_us-gaapFinancialInstrumentAxis" xlink:type="arc" order="3" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain" xlink:label="loc_us-gaapTransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaapFinancialInstrumentAxis" xlink:to="loc_us-gaapTransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain" xlink:type="arc" order="20" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain" xlink:label="loc_us-gaapTransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_10" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xbrldt:contextElement="segment" xlink:from="loc_us-gaapFinancialInstrumentAxis" xlink:to="loc_us-gaapTransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_10" xlink:type="arc" order="30" />
      <link:loc xlink:type="locator" xlink:href="gnta-20241231.xsd#GNTA_MandatoryConvertibleBondMember" xlink:label="loc_GNTAMandatoryConvertibleBondMember_10" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapTransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain" xlink:to="loc_GNTAMandatoryConvertibleBondMember_10" xlink:type="arc" order="13" />
      <link:loc xlink:type="locator" xlink:href="gnta-20241231.xsd#GNTA_ConvertibleBondMember" xlink:label="loc_GNTAConvertibleBondMember_20" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapTransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain" xlink:to="loc_GNTAConvertibleBondMember_20" xlink:type="arc" order="23" />
      <link:loc xlink:type="locator" xlink:href="gnta-20241231.xsd#GNTA_ConversionSharesMember" xlink:label="loc_GNTAConversionSharesMember_60" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapTransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain" xlink:to="loc_GNTAConversionSharesMember_60" xlink:type="arc" order="62" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_StatementScenarioAxis" xlink:label="loc_srtStatementScenarioAxis" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaapSubsequentEventTable" xlink:to="loc_srtStatementScenarioAxis" xlink:type="arc" order="4" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_ScenarioUnspecifiedDomain" xlink:label="loc_srtScenarioUnspecifiedDomain" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srtStatementScenarioAxis" xlink:to="loc_srtScenarioUnspecifiedDomain" xlink:type="arc" order="20" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_ScenarioUnspecifiedDomain" xlink:label="loc_srtScenarioUnspecifiedDomain_10" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xbrldt:contextElement="segment" xlink:from="loc_srtStatementScenarioAxis" xlink:to="loc_srtScenarioUnspecifiedDomain_10" xlink:type="arc" order="30" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_ScenarioForecastMember" xlink:label="loc_srtScenarioForecastMember_30" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srtScenarioUnspecifiedDomain" xlink:to="loc_srtScenarioForecastMember_30" xlink:type="arc" order="33" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_MeasurementInputTypeAxis" xlink:label="loc_us-gaapMeasurementInputTypeAxis" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaapSubsequentEventTable" xlink:to="loc_us-gaapMeasurementInputTypeAxis" xlink:type="arc" order="5" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_MeasurementInputTypeDomain" xlink:label="loc_us-gaapMeasurementInputTypeDomain" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaapMeasurementInputTypeAxis" xlink:to="loc_us-gaapMeasurementInputTypeDomain" xlink:type="arc" order="20" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_MeasurementInputTypeDomain" xlink:label="loc_us-gaapMeasurementInputTypeDomain_10" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xbrldt:contextElement="segment" xlink:from="loc_us-gaapMeasurementInputTypeAxis" xlink:to="loc_us-gaapMeasurementInputTypeDomain_10" xlink:type="arc" order="30" />
      <link:loc xlink:type="locator" xlink:href="gnta-20241231.xsd#GNTA_OrdinaryConversionPriceMember" xlink:label="loc_GNTAOrdinaryConversionPriceMember_80" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapMeasurementInputTypeDomain" xlink:to="loc_GNTAOrdinaryConversionPriceMember_80" xlink:type="arc" order="82" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StatementEquityComponentsAxis" xlink:label="loc_us-gaapStatementEquityComponentsAxis" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaapSubsequentEventTable" xlink:to="loc_us-gaapStatementEquityComponentsAxis" xlink:type="arc" order="6" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_EquityComponentDomain" xlink:label="loc_us-gaapEquityComponentDomain" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaapStatementEquityComponentsAxis" xlink:to="loc_us-gaapEquityComponentDomain" xlink:type="arc" order="20" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_EquityComponentDomain" xlink:label="loc_us-gaapEquityComponentDomain_10" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xbrldt:contextElement="segment" xlink:from="loc_us-gaapStatementEquityComponentsAxis" xlink:to="loc_us-gaapEquityComponentDomain_10" xlink:type="arc" order="30" />
      <link:loc xlink:type="locator" xlink:href="gnta-20241231.xsd#GNTA_AmericanDepositorySharesMember" xlink:label="loc_GNTAAmericanDepositorySharesMember_100" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapEquityComponentDomain" xlink:to="loc_GNTAAmericanDepositorySharesMember_100" xlink:type="arc" order="101" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CostOfGoodsAndServicesSold" xlink:label="loc_us-gaapCostOfGoodsAndServicesSold_140" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapSubsequentEventLineItems" xlink:to="loc_us-gaapCostOfGoodsAndServicesSold_140" xlink:type="arc" order="0" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentFaceAmount" xlink:label="loc_us-gaapDebtInstrumentFaceAmount_140" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapSubsequentEventLineItems" xlink:to="loc_us-gaapDebtInstrumentFaceAmount_140" xlink:type="arc" order="1" />
      <link:loc xlink:type="locator" xlink:href="gnta-20241231.xsd#GNTA_NumberOfBonds" xlink:label="loc_GNTANumberOfBonds_140" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapSubsequentEventLineItems" xlink:to="loc_GNTANumberOfBonds_140" xlink:type="arc" order="2" />
      <link:loc xlink:type="locator" xlink:href="gnta-20241231.xsd#GNTA_DebtInstrumentIssuePrice" xlink:label="loc_GNTADebtInstrumentIssuePrice_140" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapSubsequentEventLineItems" xlink:to="loc_GNTADebtInstrumentIssuePrice_140" xlink:type="arc" order="3" />
      <link:loc xlink:type="locator" xlink:href="gnta-20241231.xsd#GNTA_PaymentForBonds" xlink:label="loc_GNTAPaymentForBonds_140" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapSubsequentEventLineItems" xlink:to="loc_GNTAPaymentForBonds_140" xlink:type="arc" order="4" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_Capital" xlink:label="loc_us-gaapCapital_140" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapSubsequentEventLineItems" xlink:to="loc_us-gaapCapital_140" xlink:type="arc" order="5" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentInterestRateStatedPercentage" xlink:label="loc_us-gaapDebtInstrumentInterestRateStatedPercentage_140" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapSubsequentEventLineItems" xlink:to="loc_us-gaapDebtInstrumentInterestRateStatedPercentage_140" xlink:type="arc" order="6" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InvestmentInterestRatePaidInCash" xlink:label="loc_us-gaapInvestmentInterestRatePaidInCash_140" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapSubsequentEventLineItems" xlink:to="loc_us-gaapInvestmentInterestRatePaidInCash_140" xlink:type="arc" order="7" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentDescription" xlink:label="loc_us-gaapDebtInstrumentDescription_140" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapSubsequentEventLineItems" xlink:to="loc_us-gaapDebtInstrumentDescription_140" xlink:type="arc" order="8" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtConversionDescription" xlink:label="loc_us-gaapDebtConversionDescription_140" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapSubsequentEventLineItems" xlink:to="loc_us-gaapDebtConversionDescription_140" xlink:type="arc" order="9" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_Investments" xlink:label="loc_us-gaapInvestments_140" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapSubsequentEventLineItems" xlink:to="loc_us-gaapInvestments_140" xlink:type="arc" order="10" />
      <link:loc xlink:type="locator" xlink:href="gnta-20241231.xsd#GNTA_ProvisionOfBondIndenture" xlink:label="loc_GNTAProvisionOfBondIndenture_140" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapSubsequentEventLineItems" xlink:to="loc_GNTAProvisionOfBondIndenture_140" xlink:type="arc" order="11" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SharesIssued" xlink:label="loc_us-gaapSharesIssued_140" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapSubsequentEventLineItems" xlink:to="loc_us-gaapSharesIssued_140" xlink:type="arc" order="12" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StockIssued1" xlink:label="loc_us-gaapStockIssued1_140" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapSubsequentEventLineItems" xlink:to="loc_us-gaapStockIssued1_140" xlink:type="arc" order="13" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CommonStockSharesOutstanding" xlink:label="loc_us-gaapCommonStockSharesOutstanding_140" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapSubsequentEventLineItems" xlink:to="loc_us-gaapCommonStockSharesOutstanding_140" xlink:type="arc" order="14" />
    </link:definitionLink>
    <link:definitionLink xlink:type="extended" xlink:role="http://xbrl.sec.gov/ecd/role/PvpExecutiveCategoriesOnly" />
    <link:definitionLink xlink:type="extended" xlink:role="http://xbrl.sec.gov/ecd/role/PvpAdjustmentsOnly" />
    <link:definitionLink xlink:type="extended" xlink:role="http://xbrl.sec.gov/ecd/role/IndividualsOnly" />
    <link:definitionLink xlink:type="extended" xlink:role="http://xbrl.sec.gov/ecd/AwardTypeOnly">
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:label="loc_us-gaapShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" />
      <link:loc xlink:type="locator" xlink:href="gnta-20241231.xsd#GNTA_UnderswritersCommonShareWarrantsMember" xlink:label="loc_GNTAUnderswritersCommonShareWarrantsMember" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:to="loc_GNTAUnderswritersCommonShareWarrantsMember" xlink:type="arc" order="0" />
      <link:loc xlink:type="locator" xlink:href="gnta-20241231.xsd#GNTA_UnderswritersWarrantsMember" xlink:label="loc_GNTAUnderswritersWarrantsMember" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:to="loc_GNTAUnderswritersWarrantsMember" xlink:type="arc" order="10" />
      <link:loc xlink:type="locator" xlink:href="gnta-20241231.xsd#GNTA_FirstSolidCancerIndicationOptionFeeMember" xlink:label="loc_GNTAFirstSolidCancerIndicationOptionFeeMember" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:to="loc_GNTAFirstSolidCancerIndicationOptionFeeMember" xlink:type="arc" order="20" />
      <link:loc xlink:type="locator" xlink:href="gnta-20241231.xsd#GNTA_SecondSolidCancerIndicationOptionFeeMember" xlink:label="loc_GNTASecondSolidCancerIndicationOptionFeeMember" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaapShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:to="loc_GNTASecondSolidCancerIndicationOptionFeeMember" xlink:type="arc" order="30" />
    </link:definitionLink>
    <link:definitionLink xlink:type="extended" xlink:role="http://xbrl.sec.gov/ecd/role/TradingArrangementsOnly" />
</link:linkbase>
