APP and Alzheimer disease: However, in the context of AD (Jin et al., 2004a,b; Lopez-Toledano and Shelanski, 2004, 2007; Boekhoorn et al., 2006; Herran et al., 2015), transgenic mice harboring ≥3 AD-linked amyloid precursor protein (APP) mutations show higher levels of proliferation and neuronal differentiation (Jin et al., 2004a,b; Lopez-Toledano and Shelanski, 2004, 2007; Herran et al., 2015).