TNF and psoriasis: Interaction of S100A7 with RAGE activates p38 MAPK (mitogen-activated protein kinase) and ERK (extracellular signal-regulated kinase) signaling pathways, leading to production of multiple inflammatory mediators involved in psoriasis, including IL-1α, IL-1β, IL-6, IL-8, TNF-α (91, 92) (Figure 3).