APP and Alzheimer disease: Our results, especially the observation of DAPI-positive and RQC factor-positive materials in the center of amyloid plaques found in AD patient brain samples, and the ability of aberrant, CAT-tailed APP.C99 to seed Aβ-42 aggregation, support the idea proposed more than a century ago that amyloid plaques originate from within degenerating neurons or neuronal processes [80].