A number of cytokines and chemokines, which can be released by macrophages or other immune cells, are increased in AD, including interleukin-1β (IL-1β), interleukin-6 (IL-6), tumor necrosis factor α (TNFα), interleukin-8 (IL-8), transforming growth factor β, and macrophage inflammatory protein-1α (36). This evidence concerns the gene TNF and Alzheimer disease.