Gene editing with zinc finger nucleases, transcription activator-like effector nucleases, clustered regularly interspaced palindromic repeats (CRISPR)/CRISPR-associated proteins system, or meganucleases can, in principle, mediate any genome modification. Recent studies have shown that COL7A1 mutations in cells of patients with recessive dystrophic epidermolysis bullosa can be corrected by homology-directed DNA repair.