1. Department of Oncology, Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins, Baltimore, MD;
2. Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, MD;
3. Clinical Research Division, Fred Hutchinson Cancer Research Center, Seattle, WA;
4. Department of Pediatrics, University of Washington Medical Center, Seattle;
5. Division of Pediatric Hematology/Oncology, Stanford University School of Medicine, Palo Alto, CA;
6. University of Southern California Keck School of Medicine, Los Angeles;
7. Children's Oncology Group, Arcadia, CA;
8. Children's Oncology Group Statistical Office, Gainesville, FL