Similar to the effects on IL-6, the A2AAR agonist CGS 21680 significantly increased TNF release in RA but not in OA synoviocytes (10−9 M p = 0.039, 10−8 M p = 0.003, 10−7 M p = 0.002) (Figure 6). This evidence concerns the gene IL6 and rheumatoid arthritis.