Because dystrophin protects against contraction-induced injury in muscle (Blake et al., 2002; Zhao et al., 2016), reduced levels of dystrophin protein in DMD result in progressive and irreversible functional loss of skeletal and cardiac muscle, culminating in loss of ambulation by the early teens and death before 30 years of age (Asher et al., 2020; Birnkrant et al., 2018; Broomfield et al., 2021; Nascimento Osorio et al., 2019). This evidence concerns the gene DMD and Duchenne muscular dystrophy.