DMD and Duchenne muscular dystrophy: The latter mode is the mechanism of action of the FDA-approved RNA therapeutic eteplirsen (Exondys 51, Sarepta Therapeutics) for treating Duchenne muscular dystrophy, which induces the skipping of exon 51 of the mutant dystrophin gene and restoring the proper translational reading frame for dystrophin expression (Dystrophy et al., 2013).