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
IFN - α is secreted by 
Select and explain. 
A. Leucocytes, B. Fibroblasts, C. TH Cells, D. Tc Cells
A: Leucocytes
Answer: A: Leucocytes 
Explanation: IFN - α - Leucocytes
IFN - β - Fibroblasts
IFN - γ - TH & TCcells, NK Cells.