APOE-ε4 allele, especially participants with two alleles, has been associated with several biochemical processes implicated in the etiology of AD, including amyloid deposits, neurofibrillary tangles formation, neuronal cell death, oxidative stress, neuroinflammation, synaptic alterations, and cholinergic signaling dysfunction [41]. The gene discussed is APOE; the disease is Alzheimer disease.