Amyloid-beta (Aβ) is produced by the cleavage of amyloid precursor proteins in the cell membrane by β-secretase and γ-secretase into a monomeric form with peptides of different lengths such as Aβ1–40 or Aβ1–42, which is then transformed into oligomeric and fibril forms and is considered to be one of the hallmarks of Alzheimer’s disease (AD). Here, APP is linked to early-onset autosomal dominant Alzheimer disease.