APP and Alzheimer disease: Alzheimer's disease (AD) represents a major healthcare challenge of the 21st century and the leading cause of dementia[1] As a well‐known hallmark of AD pathology, amyloid‐β (Aβ) aggregation has drawn extensive attention and has been intensively studied since its discovery by Alois Alzheimer.[2] Aβ peptides are produced via the proteolytic cleavage of amyloid precursor protein (APP).