TGFB1 and rheumatoid arthritis: Moreover, the assessment of longitudinal serum samples of RA patients during CTLA4-Ig treatment showed a significant decrease of IL-6 serum levels from baseline to 6 months (p = 0.004) and 12 months of follow-up (p = 0.001), respectively, as well as TGFβ serum levels after 12 months of follow-up (p = 0.019) (Fig. 2A).