In AD, microglia surrounding the plaques to phagocyte Aβ generally manifest M2 activation phenotype and this phagocytic activity of microglia is attenuated by pro-inflammatory cytokines such as IFN-γ, IL-1β, and TNF-α, which are mainly secreted by M1 microglia (Yang et al., 2017). This evidence concerns the gene TNF and Alzheimer disease.