IL17A and psoriasis: In addition, demonstrating the increased production of IL-6 and IL-8 by IL-17F induction in the lesional skin of psoriasis patients has once again underlined the role of IL-17F in psoriasis pathogenesis.16, 17 Finally, the report that IL-17F knockout mice were associated with higher resistance to psoriasis compared to IL-17A knockout mice indicates that IL-17F is closely related to psoriasis.18