In multiple pathogenesis of AD, an important role of autophagy has been reported, for example, in generating amyloid plaques from amyloid-β (Aβ) production and accumulation via abnormally regulated amyloid precursor protein (APP) yield and in enhancing the activity of β- and/or γ-secretases, intraneuronal neurofibrillary tangles (NFT), because of tau hyper-phosphorylation and neuronal apoptosis. This evidence concerns the gene APP and Alzheimer disease.