STAT3 and rheumatoid arthritis: Chrysoeriol also inhibits the excessive proliferation of rheumatoid arthritis fibroblast-like synoviocytes (RA-FLS) by preventing the activation and phosphorylation of STAT3 (Tyr705), lowering STAT3 nuclear levels, and downregulating the expression of Bcl-2 and Mcl-1, both of which are regulated by STAT3 (50).