[Interleukin-20--a new target in psoriasis treatment].

Interleukin-20 (IL-20) is suggested as a new target in psoriasis treatment. It was first described in 2001, and the potential role of this cytokine in psoriasis was suggested because mice which were over-expressing IL-20 developed a psoriasis-like phenotype of the skin. Subsequently, IL-20 expression levels were found to be increased in psoriasis skin, and it was observed that these levels normalized upon psoriasis treatment. In the psoriasis xenograft transplantation model, administration of IL-20 to non-lesional psoriasis skin transplanted onto immune-deficient mice demonstrated that IL-20 was involved in the psoriasis induction. More interestingly, improvement of psoriasis was induced by blocking IL-20 signaling.