From a molecular perspective, AD is characterized by extracellular deposits of Aβ peptides, generated in the amyloidogenic pathway from the cleavage of APP by BACE1 and γ-secretase, and by the intracellular accumulation of strings of hyperphosphorylated Tau proteins known as neurofibrillary tangles (NFTs) [23]. The gene discussed is BACE1; the disease is Alzheimer disease.