Our findings, i.e., the increased level of IL-17A and IL-23R expression, the decreased IL-10 expression in the skin of psoriasis patients and the positive correlation between IL-23A and PASI index, suggest that IL-17, IL-23 and IL-10 may be important factors in the pathogenesis of psoriasis and could be valuable therapeutic targets. This evidence concerns the gene IL23A and psoriasis.