This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Targeted Anticancer Drugs and Immunosuppressants, Subject name: Pharmacology
Which of the following drugs inhibits de novo synthesis of purines? 
Select and explain. 
A. Cyclosporine, B. Tacrolimus, C. Mycophenolate, D. Infliximab
C: Mycophenolate
Answer: C: Mycophenolate 
Explanation: By inhibiting the enzyme IMP (Inosine 5' Monophosphate) dehydrogenase, mycophenolate inhibits the de novo synthesis of purines.