Mild cognitive impairment (MCI), a term now synonymous with prodromal AD, is an intermediate phase between normal brain aging and frank dementia when neurofibrillary tangles (NFTs) and amyloid-beta peptide (Aβ) lesions are increased in comparison to those with no cognitive impairment (NCI) (Guillozet et al., 2003; Markesbery et al., 2006; Markesbery, 2010). Here, APP is linked to Alzheimer disease.