Humans with the loss of function allele of the IL-17R signaling component ACT1 (TRAF3IP2) are more susceptible to psoriasis (Wang et al., 2013), but Act1-deficient mice are afflicted with spontaneous skin inflammatory diseases (Qian et al., 2004; Matsushima et al., 2010). This evidence concerns the gene IL17RA and inflammatory skin disease.