1 Faculty of Health Sciences, Universitat Oberta de Catalunya, Barcelona, Spain.
2 Muscle Disease Unit, Laboratory of Muscle Stem Cells and Gene Regulation, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, MD, USA.
3 Johns Hopkins University School of Medicine, Baltimore, MD, USA.
4 Muscle Disease Unit, Laboratory of Muscle Stem Cells and Gene Regulation, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, MD, USA. andrew.mammen@nih.gov.
5 Johns Hopkins University School of Medicine, Baltimore, MD, USA. andrew.mammen@nih.gov.