DMD and Duchenne muscular dystrophy: Through the induction of the skipping of exon 45, 51, or 53 in dystrophin transcripts, four AON medicines have been approved to treat DMD patients with particular mutations in the exon 43–55 hotspot, but they usually restore dystrophin protein expression to less than 1% of the normal level after a year of continuous administration [22,23,24,25,26].