In particular, having baseline IL-6 serum levels ≤ 8.4 pg/ml [(AUC: 0.735 ± 0.089) p = 0.02] (Supplementary Fig. 2A), significantly identified naïve to bDMARDs RA patients more likely to achieve DAS-defined remission under CTLA4-Ig treatment at 6 months (66.7%) compared to RA patients with baseline IL-6 serum levels > 8.4 pg/ml [15.4%, p = 0.005 (χ2 test), OR (95%Cis): 11.00 (1.75–55.82)] (Fig. 4A). Here, IL6 is linked to rheumatoid arthritis.