IL17A and rheumatoid arthritis: A recent study has suggested that iguratimod suppresses IL-17 in RA synovial fibroblast-like cells, ultimately leading to suppression of inflammation and proinflammatory cytokines regulated via IL-17.22 Iguratimod can suppress the mRNA expression of IL-17-related genes and reduce the phosphorylation of mitogen-activated protein kinases (MAPKs).