IFNG and rheumatoid arthritis: Interestingly, IFN-γ production in Th1-like Th17 cells has been shown to be repressed by miR-146a (37) and loss of function polymorphisms in the microRNA-146a (miR-146a) gene have been associated with an increased risk of developing RA and lupus in both European and Asian genetic association studies (38, 39); taken together, these data provide some mechanistic evidence that Th1-like Th17 cells are involved in the pathogenesis of RA.