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: Pathology
Macrophages are converted to epitheloid cells by which cytokine? 
Select and explain. 
A. IL-2, B. TNF-α, C. IFN-γ, D. TGF-β
C: IFN-γ
Answer: C: IFN-γ 
Explanation: IFN-γ has a major role in formation of granuloma.