This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Immunology, Subject name: Microbiology
Which is not pyrogenic - 
Select and explain. 
A. IL-1, B. TNF-a, C. IL-4, D. IL-6
C: IL-4
Answer: C: IL-4 
Explanation: Pyrogenic cytokines such as tumor necrosis factor (TNF), interleukin (IL)-1, IL-6, and interferons into the bloodstream in response to exogenous pyrogens. Reff: www.mayoclinic.com