We found that plasma IL-22 levels positively and significantly correlated with the percentage of circulating Th22 cells (Fig. 5A; P < 0.0001, R = 0.8767), but not with that of IL22+Th1 (Fig. 5B; P = 0.3482, R = −0.1523) or IL22+Th17 cells (Fig. 5C; P = 0.1946, R = −0.2095) in RA patients responsive to treatment. The gene discussed is IL22; the disease is rheumatoid arthritis.