DMD and Duchenne muscular dystrophy: The most commonly used DMD model is mdx mouse lacking the full-length dystrophin due to a nonsense point mutation (C > T) in exon 23 of Dmd. A distinction in size, mechanical loading and lifespan of either dystrophic humans or dogs and mdx mice likely implies the severity difference of muscle pathology, with mice showing only mild clinical picture and slightly reduced lifespan (Fig. 6) [99, 105].