IL-22 stimulation alone promoted phosphorylation of STAT3 (Tyr705) and p38, whereas IL-25 pre-treatment downregulated the IL-22-induced phosphorylation of STAT3 (Tyr705, Ser727), p38, and IκB-α in RA-FLS (Fig. 3a). This evidence concerns the gene NFKBIA and rheumatoid arthritis.