Advances in understanding psoriasis pathogenesis have led to the development of biologics, which are molecules directed against key cytokines incriminated in psoriasis progression (TNF-α blockers, IL-12/23p40 inhibitors, IL-23 inhibitors, IL-17A inhibitors, IL-17A/F inhibitor, and IL-17R antagonist). This evidence concerns the gene IL17RA and psoriasis.