IMURAN, generically known as azathioprine, is a medication primarily used in the management of autoimmune conditions and to prevent organ transplant rejection. It functions as an immunosuppressant, meaning it works by weakening the immune system to reduce its activity. This action helps to prevent the immune system from attacking its own tissues in autoimmune diseases or rejecting a transplanted organ. Azathioprine is often prescribed for conditions such as rheumatoid arthritis, Crohn's disease, and lupus, among others. Due to its immunosuppressive nature, patients taking IMURAN may be at an increased risk of infections and should be monitored for side effects and potential interactions with other medications.