1. Program in Targeted Therapeutics, Institute for Translational Medicine and Therapeutics and Department of Pharmacology, University of Pennsylvania School of Medicine, Philadelphia;
2. Department of Medicine, Washington University School of Medicine, St Louis, MO;
3. Centro Nacional de Investigaciones Cardiovasculares, Madrid, Spain;
4. Hematology Division, Children's Hospital of Philadelphia, PA; and
5. Department of Pathology and Laboratory Medicine, University of Pennsylvania School of Medicine, Philadelphia