APOE and Alzheimer disease: AD is an age-related neurodegenerative disorder which is characterized by the progressive accumulation in the brain parenchyma of β-amyloid A(β) plaques (Aβ peptides) and neurofibrillary tangles (tau protein), and the most widely used biomarkers for AD include the APOE genotype, CSF Aβ42, pTau and tTau, and findings from imaging setups such as MRI and PET together with a battery of cognition tests [34,58,59,60].