In addition, serum IL-2 levels in RA patients were significantly correlated with levels of other inflammatory cytokines including IL-4 (r = 0.489, p < 0.001), IL-6 (r = 0.437, p < 0.001), IL-10 (r = 0.320, p < 0.001), INF-γ (r = 0.494, p < 0.001), and TNF-α (r = 0.402, p < 0.001) (Figures 3(h)–3(l)). Here, IL4 is linked to rheumatoid arthritis.