BACE1 and Alzheimer disease: The role of BACE2 is instead controversial: on one side, BACE2 can cleave APP at theta site forming a shorter, less toxic, Aβ peptide compared to the one derived from BACE1 processing [27]; on the other side, BACE2 expression and function have been correlated with an increased neurodegeneration in Alzheimer 's disease [75, 76].