This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Chemical mediators in plasma: Kinin system, Subject name: Pathology
[{'content': 'Which of the following is not a pyrogenic cytokine? \nSelect and explain. \nA. IL - 1, B. TNF, C. IFN - a, D. IL - 18', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Pyrogens are substances which cause fever. These can be either exogenous or endogenous. The endogenous pyrogens (also called the pyrogenic cytokines) include: IL-1 IL-6 Tumor necrosis factor (TNF) Ciliary neurotopic factor (CNTF) IFN-a (alpha) IL-18 which is a member of IL-1 family does not appear to be a pyrogenic cytokine.', 'role': 'assistant'}]