S100A9 and psoriasis: Notably, the “Role of IL-17A in Psoriasis” (T2, −log(FDR) = 1.67) pathway was enriched (Fig. 3b), in which downregulated CXCL3, IL-8, S100A8, S100A9, IL17RA and CXCL1 expression was observed (Additional file 9: Figure S5, Panel C).