APP and Alzheimer disease: For AD animal models, the most frequently used models are several transgenic mice, including the double transgenic mice [67,69,74,85], triple transgenic mice [68], and 5XFAD transgenic mice [65] that overexpress specific mutant familial AD genes, such as mutant amyloid precursor protein, presenilin-1 or -2, or tau proteins, although drug-induced AD models [73] are also established.