Azathioprine

Azathioprine (INN, /ˌæzəˈθaɪɵpriːn/, abbreviated AZA) is an immunosuppressive drug used in organ transplantation and autoimmune diseases and belongs to the chemical class of purine analogues. Synthesized originally as a cancer drug and a pro-drug for mercaptopurine in 1957, it has been widely used as a immunosuppressant for more than 50 years.