Which of the following is not a pyrogenic cytokine?: (A) IL - 1, (B) TNF, (C) IFN - a, (D) IL - 18
Answer is D. 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.