Activated mast cells produce various inflammatory mediators, including histamine; lipid mediators, such as prostaglandins; growth factors; cytokines; and chemokines, such as tumor necrosis factor alpha (TNFα), interleukin (IL)-1β, IL-4, and IL-6, which are associated with the pathogenesis of AD [5]. The gene discussed is TNF; the disease is Alzheimer disease.