In light of our study suggesting that the NLRP3/caspase-1/IL-1β axis is correlated with inflammatory severity in PM patients and the MHC-I expression is NLRP3/caspase-1/IL-1β axis-dependent in vitro, we assessed the ability of MCC950 to prevent NLRP3 inflammasome activation and to alter the inflammatory response in PM model rats. This evidence concerns the gene CASP1 and polymyositis.