1. From the Departments of SurgeryPreventive Medicine, Pediatrics, and Pathology, University of Southern California School of Medicine and Children’s Hospital, Los Angeles; Department of Pediatrics, University of California School of Medicine, San Francisco; and Children’s Cancer Group Operations Center, Arcadia, CA; Department of Surgery, Children’s Hospital, Denver, CO; and Department of Pediatrics, Vanderbilt University, Nashville, TN.