There are many challenges to successful organ transplants, including matching a recipient and a donor based on matching genetic variability. It is extremely difficult to match MHC perfectly with a donor and a recipient as there are many locations where genetic differences can still cause a rejection reaction by the recipient. A familial donor is usually the closest to a perfect genetic MHC match that a recipient can find. The closer the match of genetic variability, the better the chances that the graft or transplant will be a success. When the MHC does not match between the donor and recipient, the recipient’s body is likely to perceive the transplant as a foreign invader and launch an attack of the immune system on it. This causes the
