BACE2 and Alzheimer disease: More recently, through deleting one copy of Hsa21 gene BACE2 by CRISPR-Cas9 in AD pathology-free cerebral organoids differentiated from human trisomy 21 iPSCs, Alić et al. reported an induction of AD pathology, demonstrating that BACE2 has a protective role against AD, which could be a therapeutic target [55].