The most commonly involved inflammatory markers observed in the pathogenesis of both depression and Psoriasis are IL-6, IL-17, IL-13, IL-23, IL-10, IL-1β, and type A cytokines (TNF-α, IL-2, INF-γ) through Th1 and Th17 lymphocytes mediated processes. The gene discussed is TNF; the disease is major depressive disorder.