APOE and Alzheimer disease: The neuropathological effects of APOE ε4-allele are myriad and include the following6: (1) impaired neurite outgrowth; (2) cytoskeletal disruption and hyperphosphorylation of tau; (3) mitochondrial dysfunction in neurons; (4) impaired synaptogenesis; (5) increased leakage and apoptosis in neurons; (6) brain neuropathology and impaired learning and memory in mice; and (7) Aβ peptide clearance and/or deposition, which determine their roles in the onset and progression of AD.