APP and Alzheimer disease: In AD, APP follows the amyloidogenic pathway where it is cleaved by β-site APP-cleaving enzyme 1 (BACE1) to originate amyloidogenic C-terminal derivatives (sAPPβ) [9], which are cleaved by γ-secretase, generating APP intercellular domain (AICD) and β-amyloid peptides (Aβ), including Aβ42.