The major histocompatibility complex is a :
1. series of complement-enhanced reactions to antigens
2. group of antigens, coded by a family of genes, on the surface of body cells
3. form of autoimmunity
4. the major cause of cancer
MHC, in humans, are also called as Human Leukocyte Antigen. They are vital in organ transplantations. The genes in humans are located on chromosome 6 an exhibit codominance.