Serum IL-22 levels in PsA, RA and OA were 9.22 ± 0.54 pg/ml, 9.64 ± 1.20 pg/ml and 4.45 ± 0.25 pg/ml respectively, p = ns, Kruskal Wallis ANOVA with Dunn's multiple comparison test (Figure 1). The gene discussed is IL22; the disease is rheumatoid arthritis.