IL22 and rheumatoid arthritis: In non-responding RA patients after treatment, DAS28 value positively correlated with plasma IL-22 level (Fig. 6G; P = 0.0009, R = 0.6837) and circulating Th22 cells (Fig. 6H; P = 0.0046, R = 0.6061), but no significant correlation was found between the change of DAS28 value and the change of cytokines (P ≥ 0.05) or Th subsets (P ≥ 0.05).