Administration of
immunosuppressive medications or immunosuppressants is the main method for deliberately inducing immunosuppression; in optimal circumstances, immunosuppressive drugs primarily target hyperactive components of the immune system. People in remission from cancer who require immunosuppression are not more likely to experience a recurrence. Throughout its history,
radiation therapy has been used to decrease the strength of the immune system. Dr. Joseph Murray of Brigham and Women's Hospital was given the
Nobel Prize in Physiology or Medicine in 1990 for work on immunosuppression. Immunosuppressive drugs have the potential to cause
immunodeficiency, which can increase susceptibility to
opportunistic infection and decrease
cancer immunosurveillance. Immunosuppressants may be prescribed when a normal immune response is undesirable, such as in
autoimmune diseases. Steroids were the first class of immunosuppressant drugs identified, though side-effects of early compounds limited their use. The more specific
azathioprine was identified in 1960, but it was the discovery of
ciclosporin in 1980 (together with azathioprine) that allowed significant expansion of
transplantation to less well-matched donor-recipient pairs as well as broad application to
lung transplantation,
pancreas transplantation, and
heart transplantation. ==Non-deliberate immunosuppression==