APP and amyloidosis: In this study, we introduce a novel transgenic mouse line, 5xFADXTg30XAPP-/-, which combines three key genetic modifications: the 5xFAD line, which overexpresses human FAD-mutant APP and presenilin-1 (PS1) to model amyloid pathology [16]; the Tg30 line, which drives tau pathology through human tau overexpression [17,18]; and the APP-/- line [13].