APP and Alzheimer disease: The association between Aβ and cognitive impairment has also been documented in other transgenic (Tg) animal models of AD including 3XTg-AD mice, which express three human mutant AD gene variants (PS1M146V, APPSwe, and tauP301L) and develop progressive plaques and tangles[31, 32] and the human amyloid precursor protein-overexpressing (hAPP) J20 mouse model[33].