IL17A and psoriasis: Application of imiquimod on mouse skin results in the influx of various cells of the immune system, as well as hyperplasia of the epidermis, and IMQ-induced psoriasis-like skin inflammation in mice is mediated via the IL-23/IL-17 axis and IL-1R1/MyD88 signaling.[30–32] The psoriasis model was made as previously reported,[19] mS100a7a15 mRNA level was highly expressed in IMQ-induced skin tissue (Fig 4A).