Allotransplant (allo- meaning "other" in Greek) is the transplantation of cells, tissues, or organs to a recipient from a genetically non-identical donor of the same species. The transplant is called an allograft, allogeneic transplant, or homograft. Most human tissue and organ transplants are allografts.
It is contrasted with autotransplantation (from one part of the body to another in the same person), syngeneic transplantation (grafts transplanted between two genetically identical individuals of the same species) and xenotransplantation (from other species).
Allografts can be referred to as "homostatic" if they are biologically inert when transplanted, such as bone and cartilage.An immune response against an allograft or xenograft is termed rejection. An allogenic bone marrow transplant can result in an immune attack, called graft-versus-host disease.