In this study, it was found that CSR lowers protein levels phospho-JAK2 (Tyr1007/1008), phospho-STAT3 (Tyr705), Bcl-2 and Mcl-1 and decreases STAT3 nuclear localization in IL-6/sIL-6R-stimulated RA-FLS, indicating that CSR inhibits the JAK2/STAT3 pathway in the cell model. Here, MCL1 is linked to rheumatoid arthritis.