Allotransplantation (allo- from the Greek meaning "other") is the transplantation of cells, tissues, or organs, sourced from a genetically non-identical member of the same species as the recipient.. The transplant is called an allograft or allogeneic transplant or homograft. Most human tissue and organ transplants are allografts. In contrast, a transplant from another species is called a xenograft. A transplanted organ or tissue from a genetically identical donor, for example, an identical twin,… (More on Allotransplantation)