IMQ has been reported to induce epidermal expression of IL-23, IL-17A, and IL-17F, as well as an increase in splenic Th17 cells46, and mice deficient for IL-23 or the IL-17 receptor are resistant to IMQ-induced psoriasis-like skin inflammation, demonstrating a pivotal role of the IL-23/IL-17 axis in the animal model. This evidence concerns the gene IL23A and psoriasis.