The IL-22 secretion of differentiating T cells (upon TGFβ + IL6 + IL1β + anti-IL4 treatment) from leflunomide-treated RA patients’ was higher than those of the non-leflunomide-treated RA patients’ (p = 0.0159; data not shown). Here, TGFB1 is linked to rheumatoid arthritis.