DMD and Duchenne muscular dystrophy: CRISPR/Cas9-induced single cut in the dystrophin gene of these mice and a gRNA that enables exon 51 skipping restores up to 90% dystrophin gene expression in skeletal and cardiac muscles.63 An important step toward clinical translation of therapeutic gene editing for DMD is using CRISPR/Cas9-mediated NHEJ to treat dogs with the ΔEx50 mutation, corresponding to a mutational “hotspot” in the human DMD gene.