CXCL8 and rheumatoid arthritis: Synovial fluid S100A11 was significantly correlated with the levels of IL-6 (r = 0.578, p = 0.002) and IL-8 (r = 0.740, p < 0.001) (Fig. 3g, h), but not with the levels of IL-1β, TNF-α or IL-10 in patients with RA.