ATG7 and myopathy: To confirm that LC3 staining in autophagic myopathy samples reflects an increase in the autophagosome-bound LC3-II rather than the cytoplasmic LC3-I, we performed immunoblotting for LC3 on a representative subset of muscle biopsies; ATG7 +/+ and −/− mouse embryonic fibroblasts (MEFs) were used as a positive control.