Over the years, several studies have reported increased levels of TNF, TNFR1, and TNFR2 observed in psoriatic lesions, which are produced by various cellular populations involved in the pathophysiology of psoriasis, such as keratinocytes, dendritic cells (DCs), and NKT, Th1, Th17, and Th22 cells. Here, TNF is linked to psoriasis.