This cytokine plays a pivotal role in the pathogenesis of psoriasis, which is also demonstrated by the efficacy of TNF-α-targeted therapies.74,75 TNF-α is produced by a variety of cells related to the development of psoriasis, such as keratinocytes, DCs, neutrophils, mast cells, as well as NKT, Th1, Th17 and Th22 cells.76,77 It acts on the targeted cells mainly via two types of TNF receptors, i.e., TNFRI (p55) and TNF-RII (p75). The gene discussed is TNF; the disease is psoriasis.