BACE1 is expressed in the ECs of the human BBB; it has also been shown to be predominantly localized to the membrane with an abluminal distribution of BACE1 in brain microvessels having a role in the vascular aspects of Alzheimer’s disease, particularly in the development of amyloid cerebral angiopathy (Devraj et al., 2016). This evidence concerns the gene BACE1 and early-onset autosomal dominant Alzheimer disease.