IL17A and psoriasis: Psoriasis is recognized by WHO as a “chronic, noncommunicable, painful, disfiguring, and disabling disease for which there is no cure.” At present, the estimated global prevalence reaches 3%.[1] The multifaceted etiology of psoriasis encompasses genetic predisposition, immune dysregulation, and environmental influences.[2,3] Exposure to external triggers, such as trauma, infection, and psychological stress, in conjunction with genetic susceptibility, can provoke the release of pro-inflammatory mediators by immune cells, including interleukin-17 and interleukin-23, and so on.