1. Department of Physiology, University of Pennsylvania School of Medicine, Philadelphia, PA 19104.
2. Section of Cardiology, Department of Clinical Studies, Veterinary Hospital of the University of Pennsylvania, Philadelphia, PA 19104.
3. Division of Hematology and Center for Cellular and Molecular Therapeutics, Children's Hospital of Philadelphia, and Howard Hughes Medical Institute, Philadelphia, PA 19104.
4. Department of Molecular Genetics and Microbiology, Gene Therapy Center, University of Massachusetts School of Medicine, Worcester, MA 01605.
5. Division of Medical Genetics, Gene Therapy Program, University of Pennsylvania School of Medicine, Translational Research Laboratory, Philadelphia, PA 19104.