The CRISPR/Cas9 system is a gene editing tool capable of targeting specific DNA sequences in the genome. Cas9 proteins, which are directed by molecules called single-guide RNAs to specific sites in the genome, generate mutations by introducing double-stranded DNA breaks. Until now, the CRISPR/Cas9 system and other targeted gene editing techniques were successfully applied to mammals such as mice and rats, but not to primates.