TNF and psoriasis: For instance, several pro‐inflammatory cytokines and arachidonic acid metabolic pathways described to be critical in psoriasis, such as IL‐23 (Rizzo et al, 2011), IL‐1α (Sanmiguel et al, 2009), TNF‐α (Kock et al, 1990; Kumari et al, 2013), TSLP (Volpe et al, 2014), or PTGS2 (Samuelsson, 1991), were up‐regulated.