1. Francis Owen Blood Research Laboratory, Department of Pathology and Laboratory Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC 27516.
2. Department of Pediatrics, University of Pennsylvania Medical Center, Center for Cellular and Molecular Therapeutics, Children's Hospital of Philadelphia, Philadelphia, PA 19104.
3. Department of Surgery, University of Pennsylvania Health System, Philadelphia PA 19104.
4. Departments of Pediatrics and Genetics, Stanford University, Stanford, CA 94305.
5. Spark Therapeutics, Philadelphia, PA 19104.