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
Immunosuppressant drug inhibiting the action of IL-2 without inhibiting its transcription is: 
Select and explain. 
A. Prednisolone, B. Cyclosporine, C. Tacrolimus, D. Sirolimus
D: Sirolimus
Answer: D: Sirolimus 
Explanation: Cyclosporine and tacrolimus are calcineurin inhibitors. These inhibit the formation (gene transcription) of interleukins. Sirolimus is mTOR inhibitor. It inhibits the action of interleukins after their formation.