In addition to FAD patient-derived neurons, Paquet et al., recently reported the generation of knock-in human neurons harboring heterozygous and homozygous APP or PSEN1 FAD mutations (APPKM670/671NL and PSEN1M146V) using modified CRISPR/Cas9 gene editing technology [56]. This evidence concerns the gene PSEN1 and familial Alzheimer disease.