STAT3 and rheumatoid arthritis: Furthermore, in RA Th17 cells (Figure 4S in Supplementary Files E–G) the significant correlation has been observed between expression of SMAD3 and STAT3/RORc/FOXP3 (r = 0.92, p < 0.0001, r = 0.92, p < 0.0001, r = 0.90, p < 0.0001, respectively), expression of FOXP3 and STAT3 (r = 0.91, p < 0.0001), expression of SOCS1 and STAT3 r = 0.94, p < 0.0001).