IFNG and infection: Interferon gamma (IFN-γ) signaling pathway, interleukin-1β (IL-1β) signaling, and glycolysis pathway genes were prominently activated early in infection, as were genes involved in antigen processing and presentation for major histocompatibility complex class I (MHC-I) and MHC-II; however, the upregulation of the expression of the IL-1β receptor and heat shock protein genes was limited to subjects who developed fever (124).