APP and Alzheimer disease: BACE1 suppression by RNA interference in primary cortical neurons reduces APP beta‐c‐terminal fragments (β‐CTFs) and Aβ production (Kao, Krichevsky, Kosik, & Tsai, 2004), and deficiency of BACE1 gene rescues memory deficits and cholinergic dysfunction in the Tg2576 AD model (Ohno et al., 2004).