In particular, IL-17, produced by helper T cell 17 (Th17) and γδ T cells, plays a key role in psoriasis pathogenesis by promoting hyperplasia of epidermal KC and the production of chemokines such as CXCL1, CXCL2, CXCL3, CXCL5, and CXCL8 for the recruitment of neutrophils and macrophages into psoriatic lesions [4, 5]. This evidence concerns the gene IL17A and psoriasis.