IL6 and rheumatoid arthritis: In contrast, in RA synoviocytes, the treatment with the A2AAR agonist CGS 21680 also resulted in a significant IL-6 reduction; however, only at the higher concentration of 10−8 M (CGS 21680 p = 0.002, BAY 60-6583 p < 0.001) (Figure 5).