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: Microbiology
Cytokine produced by TH1 cells 
Select and explain. 
A. IL-2, B. IL-4, C. IL-5, D. IL-6
A: IL-2
Answer: A: IL-2 
Explanation: IL-2 produced by TH1 cells induces proliferation of activated T4 cells, Tc cells and some Nk cells.