Berberine (BBR) is a drug that has been suggested as a potential treatment for RA [50], and a recent study [51] showed that BBR inhibits IL-21/IL-21R-dependent autophagy, leading to a reduction of proliferation of arthritic fibroblast-like synoviocytes, which in turn may lead to the amelioration of RA. Here, IL21 is linked to rheumatoid arthritis.