APP and neurodegenerative disease: Type I Aβ42 filaments have been previously reported as the predominant type of filaments in cases of sAD with abundant parenchymal Aβ deposition in the form of core plaques, while type II Aβ42 filaments were found predominantly in cases of FAD (AβPP V717F and PSEN1 F105L mutations), as well as in other neurodegenerative diseases, in association with parenchymal Aβ42 deposition in the form of more diffuse deposits29.