IL17A and psoriasis: Given that psoriasis is an inflammatory skin disorder characterized by epidermal hyperproliferation and abnormal keratinocyte differentiation, PPARs may be potential targets for treatment.[30] Down-regulated genes were enriched in IL-17 signaling pathway, cytokine-cytokine receptor interaction, influenza A, and nucleotide oligomerization domain like receptor signaling pathways (Fig. 3B).