In IMQ-induced psoriasis skin, both <i>S1pr2<sup>-/-</sup></i> and <i>S1pr2<sup>fl/fl</sup> K14-Cre</i> mice showed higher expressions of proinflammatory cytokines such as TNF-α, IL-17A, and IL-1β together with higher expressions of MyD88/NF-κB pathway compared to the wild-type mice. This evidence concerns the gene IL17A and psoriasis.