Fever/pyrexia refers to an elevation in the body core temperature above the hypothalamic set point (36.6°C–37.5°C) in response to pyrogens such as interleukin-1beta, interleukin-6, and tumor necrosis factor-alpha generated by infections or as a result of inflammation, graft rejection, cancer, or autoimmune reactions [4]. This evidence concerns the gene IL1B and Fever.