Answer:
MHC (major histocompatibility complex) proteins
Explanation:
Tissues are immunogically "typed" before an organ transplant to make sure and checkmate that the donor and recipient match as closely as possible in their Major histocompatibility complex (MHC).
Major histocompatibility complex (MHC) are group of genes that code for protein whose main function are to assist the immmune system recognize foreign substance. They are usually found on the surface of the cells.
