IL-17-producing T (Th17) cells are major players in the pathogenesis of psoriasis because they are present in psoriatic lesions and can induce activation/proliferation of keratinocytes and endothelial cells (Lowes et al., 2013; Skepner et al., 2014;, Sakkas and Bogdanos, 2017; Boutet et al., 2018). Here, IL17A is linked to psoriasis.