IFNG and rheumatoid arthritis: There were no statistically significant differences in IFN-γ production without IL-10 among these three groups (Fig. 2a), but the inhibitory effect of IL-10 on IFN-γ production was significantly limited in the active RA group as compared with the inactive RA group and healthy controls (percentage decrease: active RA, 2.9 ± 14.4%; inactive RA, 45.6 ± 14.4%; controls, 65.8 ± 7.9%) (Fig. 2b).