Syngenic

The word "syngenic" or "syngeneic" (from the Greek word for a relative) means genetically identical, or sufficiently identical and immunologically compatible as to allow for transplantation. For example, it may be used for something transplanted from an identical twin. When the cells are collected from the same patient on whom they will be used, it is called autologous and when collected from identical individuals, it is referred to as syngeneic. A syngeneic graft is known as an isograft.[1]

It is contrasted with Autotransplantation (from one part of the body to another in the same person), allotransplantation (from other individual of same species), and xenotransplantation (from other species).

A tumor isolated from an organism and transplanted in its syngeneic organism elicits an immune reaction leading to rejection, whereas a normal transplanted tissue won't. This signifies that tumor cells show antigens which are completely new or modified. This forms the basis of Tumor Specific Transplantation Antigens(TSTA) or Tumor Associated Transplant Antigens(TATA).