APP and early-onset autosomal dominant Alzheimer disease: Amyloid precursor protein binding protein-1 (APP-BP1) has been known to interact with the intracellular carboxyl (C-) terminus of the amyloid precursor protein (APP), the precursor protein of amyloid beta peptide (Aβ), which is the main component of neuritic plaques in Alzheimer's disease (AD) [1],[2],[3].