Knockout (KO) of an essential autophagy gene Atg7 specifically in forebrain excitatory neurons of AD mice decreases extracellular amyloid plaque formation, which is due to reduced processing and secretion of Aβ; however, these Atg7 KO mice have exacerbated memory deficits [17], suggesting that the intracellular level of amyloids, which may be regulated by autophagy, may play a key role in cognitive impairment in AD. This evidence concerns the gene ATG7 and Alzheimer disease.