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
[{'content': 'Macrophages are converted to epitheloid cells by which cytokine? \nSelect and explain. \nA. IL-2, B. TNF-α, C. IFN-γ, D. TGF-β', 'role': 'user'}, {'content': 'Answer: C \nExplanation: IFN-γ has a major role in formation of granuloma.', 'role': 'assistant'}]