Consistent with the important role of the DMD domain containing the Mark2-binding site (exon 26–30), analysis of the severity of Becker muscular dystrophy phenotype shows that mutations in the proximal rod domain of DMD (exon 10–32) causes a more severe muscle phenotype compared to mutations in the central rod domain (exon 33–45).36,37 Therefore, it may be beneficial for the development of micro-dystrophin vectors to include the Mark2 binding site in order to rescue satellite cell intrinsic defects and improving long-term efficacy. Here, DMD is linked to Becker muscular dystrophy.