IL17A and rheumatoid arthritis: We found slightly but statistically significantly increased levels of IL-17A in RA patients compared with those in control subjects (8.0 ± 46.6 pg/ml [0–462.2 pg/ml] vs 7.4 ± 17.2 pg/ml [0–97.68 pg/ml], p = 0.03, Fig. 1a).