BACE1 and early-onset autosomal dominant Alzheimer disease: β-secretaseor β-site amyloid precursor protein-cleavingenzyme 1­(BACE-1) is an essential key enzyme involved in the pathologyof Alzheimer’s disease (AD). Atype I transmembrane aspartyl protease, BACE-1, can be present inthe brain, especially in neurons, oligodendrocytes, and astrocytes.−,  BACE-1 has been found in healthy synaptic terminals and is presentat the plasma endothelial membrane and endosomal compartments.