1. From the Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester, MN; Departments of Biostatistics and Epidemiology, Pathology, and Pediatric Hematology/Oncology, University of Oklahoma Health Sciences Center, Oklahoma City, OK; Division of Hematology/Oncology, Seattle Children's Hospital, Seattle, WA; Departments of Pediatric Surgery and Pathology, University of Pittsburgh, Pittsburgh, PA; Department of Surgery, M. D. Anderson Cancer Center, Houston, TX; Tampa Children's Hospital,...