This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Immunology, Subject name: Pathology
Which of the following cytokines are not secreted by Th2 type of helper T-cells? 
Select and explain. 
A. IL-1, B. IL-4, C. IL-5, D. IL-13
A: IL-1
Answer: A: IL-1 
Explanation: Th2 type of helper T-cells Secrete IL-4, IL-5, IL-13 IL-4 stimulate Th2 cells Th2 cells in turn cause stimulation of IgE production, activation of mast cells and eosinophils Mainly involved in allergies and defense against helminthic infestations