1. Department of Medicine; Duke University Medical Center; Durham North Carolina
2. Division of Hematology; Department of Medicine; Duke Comprehensive Sickle Cell Center, Duke University Medical Center; Durham North Carolina
3. Division of Hematology/Oncology and UNC Sickle Cell Center; Department of Medicine; University of North Carolina at Chapel Hill; Chapel Hill North Carolina
4. Department of Medicine; Emory University Medical Center; Atlanta Georgia