APP and Alzheimer disease: Additional neuropathological hallmarks of AD are the presence of extracellular β-amyloid (Aβ) plaques and intracellular neurofibrillary tangles (NFTs) resulting from the deregulation of Amyloid Precursor Protein (APP) and the increasing of Phosphorylated-Tau (P-Tau) protein, respectively (Yacoubian, 2017).