IL17A and psoriasis: Lymphocytes play a crucial role in cytokine production and abnormally elevated neutrophils in psoriasis can secrete a variety of proinflammatory factors (e.g., IL‐17/IL‐6/TNF) to participate in the movement and progression of psoriasis, which in turn can act on neutrophils to promote their chemotaxis, aggregate in the epidermis and dermis, and aggravate the inflammatory damage of psoriasis [7, 8].