Overview of Transplantation By Martin Hertl, MD, PhD, Rush University Medical Center Reviewed / Revised Aug 2022 | Modified Sep 2022 View Patient Education Pretransplantation Screening Posttransplantation Immunosuppression Posttransplantation Complications More Information Topic Resources Immunosuppressants Used to... Manifestations of Transplant... Transplants may be The patient's own tissue (autografts; eg, bone, bone marrow, and skin grafts) Genetically identical (syngeneic [between monozygotic twins]) donor tissue (isografts) Genetically dissimilar donor tissue (allografts, or homografts) Rarely, grafts from a different species (xenografts, or heterografts) Transplanted tissue may be Cells (as for hematopoietic stem cell [HSC] transplants, lymphocyte transplants, and pancreatic islet cell transplants) Parts or segments of an organ (as for liver or pulmonary lobar transplants and skin grafts) Entire organs (as for heart transplants, kidney transplants, hand / facial transplants, and uterine transplants) Tissues (eg, composite tissue grafts, corneas) Tissues may be grafted to an anatomically normal site (orthotopic; eg, heart transplants) or abnormal site (heterotopic; eg, a kidney transplanted into the iliac fossa).