The dystrophin gene consists of eight promoters and 79 exons to generate a ~11.4 kb cDNA and 427 kDa muscle isoform protein.321 Mutations typically lead to a truncated protein in DMD patients.321 The large dystrophin cDNA size poses a major challenge to rAAV-based gene replacement therapy because it exceeds the packaging capacity, so strategies have focused on identifying the minimally required protein sequences. This evidence concerns the gene DMD and Duchenne muscular dystrophy.