PSEN1 and Alzheimer disease: Transgenic mouse models mimicking Alzheimer's disease are useful for studying disease mechanisms [32], most of which were based on the overexpression of mutated forms of human amyloid-β protein precursor (AβPP) or in combination with mutated human presenilin 1 (PS1) or 2 (PS2) genes [28], presenting typical histopathological features of AD.