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  <xs:element id="xncr_NumberOfCollaborationAndLicenseAgreement" abstract="false" name="NumberOfCollaborationAndLicenseAgreement" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="xbrli:integerItemType"/>
  <xs:element id="xncr_CollaborativeArrangementPercentageEquityPrivateCompany" abstract="false" name="CollaborativeArrangementPercentageEquityPrivateCompany" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:percentItemType"/>
  <xs:element id="xncr_NoncashOrPartNoncashAcquisitionNoncashFinancialOrEquityInstrumentConsiderationShareValue" abstract="false" name="NoncashOrPartNoncashAcquisitionNoncashFinancialOrEquityInstrumentConsiderationShareValue" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="xncr_CollaborativeAgreementBispecificDrugDevelopmentNumberOfCandidates" abstract="false" name="CollaborativeAgreementBispecificDrugDevelopmentNumberOfCandidates" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:integerItemType"/>
  <xs:element id="xncr_SaleOfAdditionalCommonStockTextBlock" abstract="false" name="SaleOfAdditionalCommonStockTextBlock" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:textBlockItemType"/>
  <xs:element id="xncr_DeferredRevenuePolicyTextBlock" abstract="false" name="DeferredRevenuePolicyTextBlock" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:textBlockItemType"/>
  <xs:element id="xncr_XtendFcTechnologyLicenseAgreementMember" abstract="true" name="XtendFcTechnologyLicenseAgreementMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="xncr_MarketableSecuritiesImpairmentLossesAndRecoveries" abstract="false" name="MarketableSecuritiesImpairmentLossesAndRecoveries" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="xncr_MiragenViridianMember" abstract="true" name="MiragenViridianMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="xncr_RegulatoryBasedMilestonesMember" abstract="true" name="RegulatoryBasedMilestonesMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="xncr_PercentageOfFundingForDevelopmentCosts" abstract="false" name="PercentageOfFundingForDevelopmentCosts" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="dtr-types:percentItemType"/>
  <xs:element id="xncr_DeferredTaxAssetsCapitalizedLeaseAssets" abstract="false" name="DeferredTaxAssetsCapitalizedLeaseAssets" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="xncr_TopVendorMember" abstract="true" name="TopVendorMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="xncr_SecondCollaborationAndLicenseAgreementMember" abstract="true" name="SecondCollaborationAndLicenseAgreementMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="xncr_ShareBasedCompensationArrangementByShareBasedPaymentAwardSubsequentTermOfPlan" abstract="false" name="ShareBasedCompensationArrangementByShareBasedPaymentAwardSubsequentTermOfPlan" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:durationItemType"/>
  <xs:element id="xncr_VirBiotechnologyMember" abstract="true" name="VirBiotechnologyMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="xncr_PercentageOfCoDetailingActivities" abstract="false" name="PercentageOfCoDetailingActivities" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="dtr-types:percentItemType"/>
  <xs:element id="xncr_InmuneBioIncMember" abstract="true" name="InmuneBioIncMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="xncr_ShareBasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsCommonStockFairValuePerShareMaximum" abstract="false" name="ShareBasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsCommonStockFairValuePerShareMaximum" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:perShareItemType"/>
  <xs:element id="xncr_CollaborationAndLicensingProgramsAxis" abstract="true" name="CollaborationAndLicensingProgramsAxis" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrldt:dimensionItem" type="xbrli:stringItemType"/>
  <xs:element id="xncr_ShareBasedCompensationArrangementByShareBasedPaymentAwardPurchasePriceOfCommonStockPercentageOnInitialOfferingDate" abstract="false" name="ShareBasedCompensationArrangementByShareBasedPaymentAwardPurchasePriceOfCommonStockPercentageOnInitialOfferingDate" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:percentItemType"/>
  <xs:element id="xncr_PropertyPlantAndEquipmentUsefulLifeTableTextBlock" abstract="false" name="PropertyPlantAndEquipmentUsefulLifeTableTextBlock" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:textBlockItemType"/>
  <xs:element id="xncr_Xmab306ProductMember" abstract="true" name="Xmab306ProductMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="xncr_EquitySecuritiesFvNiTableTextBlock" abstract="false" name="EquitySecuritiesFvNiTableTextBlock" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:textBlockItemType"/>
  <xs:element id="xncr_ThirdRangeOfParticipatingEmployeeContributionsMember" abstract="true" name="ThirdRangeOfParticipatingEmployeeContributionsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="xncr_MajorCustomersMember" abstract="true" name="MajorCustomersMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="xncr_ScheduleOfAccountsReceivableCollectionPeriodTable" abstract="true" name="ScheduleOfAccountsReceivableCollectionPeriodTable" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrldt:hypercubeItem" type="xbrli:stringItemType"/>
  <xs:element id="xncr_AntibodyLibrariesLicenseAgreementMember" abstract="true" name="AntibodyLibrariesLicenseAgreementMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="xncr_ScheduleOfRevenueByMajorLicenseesTableTextBlock" abstract="false" name="ScheduleOfRevenueByMajorLicenseesTableTextBlock" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:textBlockItemType"/>
  <xs:element id="xncr_RentExpenseAnnualPercentageIncrease" abstract="false" name="RentExpenseAnnualPercentageIncrease" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:percentItemType"/>
  <xs:element id="xncr_ProceedsFromMilestonePaymentReceived" abstract="false" name="ProceedsFromMilestonePaymentReceived" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="xncr_DeferredTaxLiabilitiesLicenseCosts" abstract="false" name="DeferredTaxLiabilitiesLicenseCosts" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="xncr_SharebasedCompensationArrangementBySharebasedPaymentAwardNumberOfPurchasePeriods" abstract="false" name="SharebasedCompensationArrangementBySharebasedPaymentAwardNumberOfPurchasePeriods" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="xbrli:integerItemType"/>
  <xs:element id="xncr_LesseeOperatingLeaseNumberOfLeases" abstract="false" name="LesseeOperatingLeaseNumberOfLeases" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:integerItemType"/>
  <xs:element id="xncr_CollaborationAndLicensingProgramsDomain" abstract="true" name="CollaborationAndLicensingProgramsDomain" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="xncr_DefinedContributionPlanVestingPeriod" abstract="false" name="DefinedContributionPlanVestingPeriod" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:durationItemType"/>
  <xs:element id="xncr_InitialMonthlyBaseRent" abstract="false" name="InitialMonthlyBaseRent" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="xncr_LicenseDevelopmentAndCommercializationAgreementMember" abstract="true" name="LicenseDevelopmentAndCommercializationAgreementMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="xncr_FiniteLivedAndIndefiniteLivedIntangibleAssetsByMajorClassLineItems" abstract="true" name="FiniteLivedAndIndefiniteLivedIntangibleAssetsByMajorClassLineItems" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:stringItemType"/>
  <xs:element id="xncr_CollaborativeAgreementPercentageOfResponsibilityAssumedForDevelopmentCosts" abstract="false" name="CollaborativeAgreementPercentageOfResponsibilityAssumedForDevelopmentCosts" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:percentItemType"/>
  <xs:element id="xncr_FirstRangeOfParticipatingEmployeeContributionsMember" abstract="true" name="FirstRangeOfParticipatingEmployeeContributionsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="xncr_NumberOfPrimaryCriteriaToDetermineCapitalizationOfPatent" abstract="false" name="NumberOfPrimaryCriteriaToDetermineCapitalizationOfPatent" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:integerItemType"/>
  <xs:element id="xncr_EquityIncentivePlan2013Member" abstract="true" name="EquityIncentivePlan2013Member" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="xncr_CollaborationAndLicenseAgreementMember" abstract="true" name="CollaborationAndLicenseAgreementMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="xncr_CashConsiderationOnSaleOfOption" abstract="false" name="CashConsiderationOnSaleOfOption" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="xncr_CollaborativeArrangementStandaloneSellingPrice" abstract="false" name="CollaborativeArrangementStandaloneSellingPrice" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="xncr_AstellasMember" abstract="true" name="AstellasMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="xncr_AccountsReceivableCollectionPeriod" abstract="false" name="AccountsReceivableCollectionPeriod" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:durationItemType"/>
  <xs:element id="xncr_TechnologyLicenseAgreementMember" abstract="true" name="TechnologyLicenseAgreementMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="xncr_CatabasisPharmaceuticalsIncMember" abstract="true" name="CatabasisPharmaceuticalsIncMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="xncr_CollaborationResearchAndLicensingAgreementsDisclosureAbstract" abstract="true" name="CollaborationResearchAndLicensingAgreementsDisclosureAbstract" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:stringItemType"/>
  <xs:element id="xncr_MilestoneMember" abstract="true" name="MilestoneMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="xncr_EquityReceivedInConnectionWithSaleOfFinancialAssets" abstract="false" name="EquityReceivedInConnectionWithSaleOfFinancialAssets" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="xncr_GileadMember" abstract="true" name="GileadMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="xncr_IncomeTaxTable" abstract="true" name="IncomeTaxTable" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrldt:hypercubeItem" type="xbrli:stringItemType"/>
  <xs:element id="xncr_NumberOfDiscoveryProgramsInClinicalDevelopment" abstract="false" name="NumberOfDiscoveryProgramsInClinicalDevelopment" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="xbrli:integerItemType"/>
  <xs:element id="xncr_NumberOfSharesAcquired" abstract="false" name="NumberOfSharesAcquired" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:sharesItemType"/>
  <xs:element id="xncr_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsCommonStockFairValuePerShareMinimum" abstract="false" name="ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsCommonStockFairValuePerShareMinimum" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:perShareItemType"/>
  <xs:element id="xncr_PatentsPendingIssuanceMember" abstract="true" name="PatentsPendingIssuanceMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="xncr_AimmuneMember" abstract="true" name="AimmuneMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="xncr_DeferredTaxLiabilitiesCapitalizedLegalCosts" abstract="false" name="DeferredTaxLiabilitiesCapitalizedLegalCosts" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="xncr_ScheduleOfStockOptionsOutstandingTableTextBlock" abstract="false" name="ScheduleOfStockOptionsOutstandingTableTextBlock" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:textBlockItemType"/>
  <xs:element id="xncr_EffectiveIncomeTaxRateReconciliationChangeInStateRateAmount" abstract="false" name="EffectiveIncomeTaxRateReconciliationChangeInStateRateAmount" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="xncr_JanssenMember" abstract="true" name="JanssenMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="xncr_MorphoSysMember" abstract="true" name="MorphoSysMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="xncr_ShareBasedCompensationArrangementByShareBasedPaymentAwardPercentageOfCompensationWithheldToPurchaseSharesAtDiscount" abstract="false" name="ShareBasedCompensationArrangementByShareBasedPaymentAwardPercentageOfCompensationWithheldToPurchaseSharesAtDiscount" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="dtr-types:percentItemType"/>
  <xs:element id="xncr_CollaborativeArrangementNumberOfTargetPrograms" abstract="false" name="CollaborativeArrangementNumberOfTargetPrograms" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:integerItemType"/>
  <xs:element id="xncr_NoncashConsiderationReceivedFromRevenueContracts" abstract="false" name="NoncashConsiderationReceivedFromRevenueContracts" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="xncr_JohnsonJohnsonInnovationJjdcInc.Member" abstract="true" name="JohnsonJohnsonInnovationJjdcInc.Member" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="xncr_AlexionPharmaceuticalsIncMember" abstract="true" name="AlexionPharmaceuticalsIncMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="xncr_OptionAndLicenseAgreementMember" abstract="true" name="OptionAndLicenseAgreementMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
</xs:schema>
