BACE2, also called Asp1 (aspartyl protease 1) or memapsin 1 (membrane-anchored aspartic protease of the pepsin family), is a transmembrane aspartic protease and the homolog BACE1, the well-known enzyme implicated in Alzheimer’s disease that cleaves the Amyloid β Precursor Protein (APP). Here, BACE2 is linked to early-onset autosomal dominant Alzheimer disease.