human histocompatibility antigens

Human histocompatibility antigens are proteins found on the surface of our cells that help the immune system distinguish between the body’s own cells and foreign invaders. These antigens are primarily part of the major histocompatibility complex (MHC) and are crucial in organ transplantation, as they determine whether a transplant will be accepted or rejected. They also play a role in immune responses to infections and in autoimmune diseases. Essentially, these antigens act as a "cellular ID badge," guiding the immune system to recognize which cells belong to the body and which do not.