Tissue and Organ ProcurementTissue DonorsDeltaretrovirus InfectionsDeltaretrovirus AntibodiesNucleic Acid Amplification TechniquesBlood DonorsLiving DonorsNational Institutes of Health (U.S.)United StatesOrgan TransplantationNational Health ProgramsNational Library of Medicine (U.S.)National Cancer Institute (U.S.)Multiple Organ FailureOrgan SizeNational Center for Health Statistics (U.S.)Time FactorsOrgan SpecificityOrgan of CortiTissue and Organ HarvestingGraft SurvivalRisk FactorsLiver TransplantationHealth Surveys