This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Pharmacology
The immunosuppressant action of cyclosporine appears to be due to : 
Select and explain. 
A. Activation of NK cells, B. Blockade of tissue responses to inflammatory mediators, C. Inhibition of gene transcription of interleukins, D. Interference with antigen recognition
C: Inhibition of gene transcription of interleukins
Answer: C: Inhibition of gene transcription of interleukins 
Explanation: Cyclosporine and tacrolimus acts by inhibiting calcineurin, which is involved in the activation of NFAT. Final result of this process is increased transcription of IL-2 gene.
Sirolimus does not inhibit the transcription of IL-2 but interferes with its action. It inhibits the enzyme tyrosine kinase, known as mTOR (which is activated by IL-2).