Regarding autoimmune diseases such as psoriasis, the various immune cell subpopulations associated with the EIME work synergistically to release cytokines, such as TNF-α, IFN-γ, IL-17A, and IL-22, which interact with each other and their secreted inflammatory factors, to create a pro-inflammatory environment within the skin that A dynamic immune homeostasis is maintained. The gene discussed is IL17A; the disease is psoriasis.