APP and Alzheimer disease: Aβ-deposition is exacerbated with Ldlr-deficiency in AD mice (Tg2576 and APP/PS1; Cao et al., 2006; Katsouri and Georgopoulos, 2011) and is attenuated with Ldlr overexpression on an APP/PS1 background due to enhanced clearance (Kim et al., 2009).