APP and Alzheimer disease: Amyloid plaques caused by an amyloid precursor protein (APP) gene mutation, neurofibrillary tangles (NFT) caused by tau protein gene mutation, missense mutations of the presenilin-1 (PS-1) gene, and the apolipoprotein E typeE4 (ApoE4) allele are closely associated with Alzheimer’s disease [75,76,77,78].