Increased levels of circulating pro-inflammatory cytokines, such as IL-1α, IL-1β, IL-6, and TNF-α, complement and the presence of activated microglia, have been described in patients with AD, and a direct correlation has been established between Aβ-induced neurotoxicity and cytokine production, and between AD progression, rapid cognitive decline and peripheral immunity and inflammation [88]. This evidence concerns the gene TNF and Alzheimer disease.