IL6 and rheumatoid arthritis: As found in Figures 2E-H, the levels of pro-inflammatory cytokines IL-6 and TNF-α were markedly higher and the levels of anti-inflammatory cytokines IL-13 and IL-10 were lower in the RA-FLS + M0 + TNF-α group than in the RA-FLS + M0 group, whereas GW4869 addition increased the levels of IL-6 and TNF-α and lowered the levels of IL-13 and IL-10 in the RA-FLS + M0 + TNF-α group.