APP and Alzheimer disease: Amyloid β1–42 (Aβ1–42) peptide is the major component of amyloid plaques,extracellularformations that are commonly observed in the gray matter of patientsdiagnosed with Alzheimer’s disease (AD).1,2 Thispeptide is produced by γ-secretases from amyloid precursor protein.3−6 Numerous in vitro studies demonstrated that freeAβ1–42 rapidly aggregates at physiologicalconditions producing oligomers and fibrils.7−11 These highly toxic aggregates can spread across thebrain causing progressive neurodegeneration12−15