We injected sgRNA-Psen1-P436 (60 ng/μl) (Fig. 1a, b) together with either BE or Target-AID mRNA (200 ng/μl) into the cytoplasm of C57BL/6J mouse zygotes to generate mutant mice carrying Psen1-P436S, which has been identified in fAD patients13. Here, AICDA is linked to familial Alzheimer disease.