1. Childhood Cancer Research Unit, Department of Women's and Children's Health, Karolinska Institutet, Karolinska University Hospital Solna, Stockholm, Sweden;
2. Department of Pediatric Hematology Oncology, Azienda Ospedaliero Universitaria A. Meyer, Florence, Italy;
3. Department of Pediatrics, Leiden University Medical Center, Leiden, The Netherlands;
4. Children's Hospital Medical Center, Cincinnati, OH;
5. St Anna Children's Hospital, Vienna, Austria;
6. Children's Research Hospital, Kyoto City Institute of Health and Environmental Sciences, Kyoto, Japan;
7. Children's Research Institute, Washington, DC;
8. Great Ormond Street Hospital, London, United Kingdom; and
9. Department of Hematology and Oncology, Children's University Hospital, Hamburg, Germany