NOS1 and Duchenne muscular dystrophy: The importance of NO in muscle repair also emerges from the observation that nNOS signalling is defective in many genetically diverse skeletal muscle diseases in which muscle repair is dysregulated, including Duchenne muscular dystrophy, Becker muscular dystrophy, limb-girdle muscular dystrophies 2C, 2D and 2E, Ullrich congenital muscular dystrophy and inflammatory myositis [3,10-13].