1. University of Pittsburgh, Pittsburgh, PA
2. Columbia University, New York, NY
3. Howard University Center for Sickle Cell Disease, Washington, DC
4. Medical College of Wisconsin and Blood Center of Wisconsin, Milwaukee, WI
5. National Institutes of Health, Bethesda, MD
6. Wake Forest University, Winston-Salem, NC
7. University of Illinois Chicago Chicago, IL
8. Children's Hospital & Research Center Oakland, Oakland, CA
9. Boston University, Boston, MA