Duchenne muscular dystrophy (DMD) is caused by mutations in the dystrophin gene and afflicts skeletal and cardiac muscles. Previous studies showed that DMD is associated with constitutive activation of NF-κB, and in dystrophin-deficient mdx and utrophin/dystrophin (utrn (-/-) ;mdx) double knock out (dko) mouse models, inhibition of NF-κB with the Nemo Binding Domain (NBD) peptide led to significant improvements in both diaphragm and cardiac muscle function.