This mechanism is thought to play a role in the pathogenesis of anti-CTLA4-mediated hypophysitis by binding abundantly expressed CTLA4 antigen in the pituitary, activating complement, and causing development of complement-dependent antibody-mediated cytotoxicity (CDC) against cells secreting thyrotropin, follicle-stimulating hormone or corticotropin. Here, CTLA4 is linked to hypophysitis.