Leukin 50 mg Tablet contains Mercaptopurine, a chemotherapy and immunosuppressive medicine primarily used in the treatment of Acute Lymphoblastic Leukemia (ALL). It works by inhibiting the growth and multiplication of abnormal white blood cells, helping to bring the disease under control. As a purine antagonist, Mercaptopurine interferes with the synthesis of DNA and RNA, making it effective in halting the spread of cancerous cells. Leukin is also sometimes prescribed in autoimmune conditions like Crohn’s disease and ulcerative colitis under strict medical supervision. Regular blood tests are essential while on this medication to monitor liver function and blood counts. This tablet should be taken exactly as prescribed by a physician, and any signs of infection, unusual bleeding, or fatigue should be promptly reported.