While most cytokines (TNFα, IL-6, TGFβ1, etc.)do not play a major role in prion-induced neurodegeneration, deficiency of IL-1 receptor 1 (IL-1R1, C57BL/6J, infected with 139A; B6;129S1/Sv, infected with RML), the receptor for IL-1α and IL-1β, caused a mild but statistically significant delay of disease progression [108,109], suggesting a detrimental role of IL-1R signaling in prion disease. This evidence concerns the gene IL1A and prion disease.