following Suppression of Aβ Production in a Transgenic Model of Alzheimer Disease Persistent Amyloid in Tet-Off APP Mice Abstract Background The proteases (secretases) that cleave amyloid-β (Aβ) peptide from the amyloid precursor protein (APP) have been the focus of considerable investigation in the development of treatments for Alzheimer disease. The prediction has been that reducing Aβ product