TNF and psoriasis: Given the critical role of IL-17A in psoriasis pathogenesis, it is not surprising that the IL-17A inhibitors secukinumab and ixekizumab are associated with complete or near complete skin clearance in many patients and have demonstrated efficacy that is superior to many other agents (i.e., TNF-α inhibitors and ustekinumab) [27, 95, 121].