Two loci of interest for potential therapeutic applications, previously chosen to investigate other tailored-made nucleases [25], DMD (gene involved in the Duchenne Muscular Dystrophies) and RAG1 (V(D)J recombination-activating protein 1), were selected in the human genome and an additional locus of interest for bioproduction, the fucosyltransferase 8 (FUT8) gene, was chosen in the Chinese hamster genome. The gene discussed is RAG1; the disease is Duchenne muscular dystrophy.