IFNG and Arthritis: Abdollahi-Roodsaz et al. reported that IL-1 receptor antagonist (IL-1rn−/−) knockout mice showed severe arthritis with reduced Tregs function and an up-regulation of IFN-γ production, whereas IL-1rn−/−Tlr4−/− mice showed a suppression of severe arthritis with reduced numbers of Th17 cells [84].