PAX7 and Duchenne muscular dystrophy: Co-immunostaining for BMI1, PAX7, and MYF5 showed that the decrease of BMI1+cells affected both PAX7+; MYF5− quiescent and PAX7−; MYF5+ committed myoblasts in older DMD patients (Figures 1A, 1C, and 1D), while no difference was seen in younger patients (Figures 1A, 1C, and 1D).