1. Klinikum Stuttgart, Olgahospital, Pädiatrie 5 (Onkologie, Hämatologie, Immunologie), Stuttgart; and Universitätsklinikum Münster, Pädiatrische Hämatologie und Onkologie, Münster, Germany
2. Division of Hematology-Oncology, Stanford University Medical Center & Lucile Packard Children's Hospital, Palo Alto, CA
3. Sezione di Chemioterapia, Istituto Ortopedico Rizzoli, Bologna, Italy
4. Center for Cancer Research, National Institutes of Health, Bethesda, MD
5. Division of Cancer Medicine and Radiotherapy, The Norwegian Radium Hospital, Rikshospitalet University Hospital, Oslo, Norway
6. Department of Oncology, University College Hospital, London, United Kingdom
7. Division of Oncology, Children's National Medical Center, George Washington University, Washington, DC