APP and familial Alzheimer disease: Forms of amyloid precursor protein (APP) with familial AD (FAD)-associated V642 mutations, such as V642 to I (London FAD mutation), F (Indiana FAD mutation) and to G (no FAD associated), have an increased capability to activate Gαo, with this activation resulting in apoptosis and associated DNA fragmentation (Okamoto et al., 1995; Yamatsuji et al., 1996a,b).