In our study, stratifying the whole RA cohort based on the achievement of DAS remission at 6 months under CTLA4-Ig treatment, we found that RA patients achieving this clinical outcome had, at baseline of CTLA4-Ig therapy, significantly lower serum levels of IL6 compared to RA patients not achieving the same clinical outcome, identifying a cut-off value of 8.4 pg/ml for IL-6 serum levels characterizing RA patients with the lowest chance of DAS remission achievement at 6 months of CTLA4-Ig therapy, regardless of disease duration. Here, CTLA4 is linked to rheumatoid arthritis.