<prompt> Most important pyogenic Interleukin is?IL-21L-1IL-6IL-8  <response>: Ans. b 1L-1Ref: J Infect Dis. 1999 179 Supplement 2: S294-S304. doi: 10.1086513856, Harrison 18th ed:2666Following cytokines are intrinsically pyrogenic in that they produce a rapid-onset fever by acting directly on the hypothalamus without the requirement for the formation of another cytokine:IL-1a,TNF-a,TNF-b,IFN-a,and IL-6.PLEASE NOTE: IL-18 of IL-1 family is not pyrogenic 