DMD and Duchenne muscular dystrophy: This has led to efforts to restore the disrupted dystrophin reading frame in DMD patients by skipping non-essential exons during mRNA splicing, thereby producing internally deleted, but still partially or fully functional, dystrophin proteins.19,26,27 In contrast to a transient method targeting the dystrophin mRNA, the correction of the dystrophin reading frame in the genome by transiently expressed TALENs would lead to permanently restored dystrophin expression by each modified cell and all of its progeny.