Moreover, 50 mg/kg cinnamtannin D1, a polyphenolic compound isolated from Cinnamomum tamala, alleviates the severity of RA, affording reduced clinical scores and paw swelling; reduces inflammatory cell infiltration, cartilage damage in the joints, and IL-17, IL-6, and IL-1β; enhances TGF-β and IL-10 levels; reduces the frequency of Th17 cells; and enhances the frequency of Treg cells, namely by its potential to inhibit aryl hydrocarbon receptor expression and phospho-STAT3/RORγt [350]. This evidence concerns the gene IL17A and rheumatoid arthritis.