This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Other topics and Adverse effects, Subject name: Anatomy
[{'content': 'Which of the following drugs is used as an immunosuppressive but lacks anticancer activity \nSelect and explain. \nA. Methotrexate, B. 6-mercaptopurine, C. Azathioprine, D. 5-flurouracil', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Ref-KDT 6/e p819,820,838 Azathioprine is an an antimetabolite that is used as an immunosuppressant but not as an antineoplastic drug. It is a product and this conveed to its active metabolite in the Lymphoid Cells only', 'role': 'assistant'}]