BACE1 and Alzheimer disease: Since accumulation and aggregation of Aβ are considered to be the critical initiator for the progression of AD, Aβ is predicted to be an efficient target for the drug therapies for AD (Vassar, 2004), such as inhibition of the enzymatic activity of BACE1 for reducing cerebral levels of Aβ (Karran et al., 2011).