In the first steps of infection, resident macrophages and mast cells release inflammatory mediators, such as cytokines (e.g., interleukin-1β (IL-1β), IL-6, IL-12, and the chemokine IL-8), tumor necrosis factors (e.g., TNF-α and TNF-β), interferons (e.g., IFN-γ), eicosanoids (e.g., prostaglandins and leukotrienes) and vasoactive amines (e.g., histamine) [7]. The gene discussed is TNF; the disease is infection.