KCNH1 and rheumatoid arthritis: Overall, nitidine chloride restrained aggressive and inflammatory role of rheumatoid arthritis FLSs through targeting KCNH1 and sequential suppression of AKT phosphorylation, manifesting that nitidine chloride may control FLS-mediated rheumatoid synovial inflammation and joint destruction and be a new therapeutical drug for rheumatoid arthritis.