Considering the pooled cohorts of naive RA and RA in remission, IL-6 plasma levels directly correlated with the IHC scores for lining CD68+ (R = 0.47; p < 0.001), lining CD3+ (R = 0.34; p = 0.002) and lining CD20+ (R = 0.35; p = 0.002) cells (Fig. 2E) and with the IHC scores for sublining CD68+ (R = 0.46; p < 0.001), sublining CD21+ (R = 0.36; p = 0.001), sublining CD3+ (R = 0.39; p < 0.001) and sublining CD20+ (R = 0.37; p = 0.001) cells (Fig. 2F). Here, CR2 is linked to rheumatoid arthritis.