IL21 and rheumatoid arthritis: Among the 14 plasma cytokines (IL-2, IL-4, IL-5, IL-6, IL-9, IL-10, IL-13, IL-17A, IL-17F, IL-21, IL-22, INF-γ, TGF-β, and TNF-α) analyzed by using flow-cytometry, the levels of IL-6, IL-10, IL-17A, and TNF-α were significantly lower in clinical remission as compared to the active RA group.