Myostatin is known to activate the phosphatidylinositol 3‐kinase (PI3K)-Akt signaling pathway and interleukin (IL)-1β pathway in RA synovial fibroblasts, inducing pro-inflammatory cytokines such as tumor necrosis factor‐α (TNF-α) and IL-69,25. Here, MSTN is linked to rheumatoid arthritis.