APOE and Alzheimer disease: The pathogenesis of AD links the expression of ApoE4 to amyloid precursor protein (APP) processing and amyloid-beta (Aβ) peptide accumulation by a reduction in (Aβ)/amyloid clearance, increased (Aβ) production, and specifically increased toxic Aβ oligomer formation and acceleration during the early seeding stage of (Aβ) aggregation6.