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: Medicine
IL-2 is secreted by: 
Select and explain. 
A. CD4 and lymphocytes, B. CD8 cells, C. Macrophages, D. Neutrophils
A: CD4 and lymphocytes
Answer: A: CD4 and lymphocytes 
Explanation: Answer is A (CD4 and lymphocytes) : IL-2 is produced by T helper (CD4) lymphocytes