1. Paediatric Hematology and Oncology, St Anna Children's Hospital, Vienna, Austria;
2. Paediatric Hematology and Oncology, University of Padova, Padova, Italy;
3. Paediatric Hematology and Oncology, Cambridge University Hospitals Foundation Trust, Addenbrooke's Hospital, Cambridge, United Kingdom;
4. Paediatric Hematology and Oncology, University of Leuven, Leuven, Belgium;
5. Paediatric Hematology and Oncology, University of Goteborg, Goteborg, Sweden;
6. Pathology, Hôpital Purpan, Toulouse, France;
7. National Hospital Organization Nagoya Medical Center, Aichi, Japan;
8. Department of Bone Marrow Transplantation and Childhood Oncology and Hematology, Medical University of Wroclaw, Wroclaw, Poland;
9. Paediatric Hematology and Oncology, Erasmus MC–Sophia Children's Hospital, Rotterdam, The Netherlands;
10. NHL-BFM Study Centre, Paediatric Hematology and Oncology, Justus Liebig University, Giessen, Germany;
11. Biostatistics and Epidemiology Unit, Institute Gustave-Roussy, Villejuif, France;
12. Université Paris-Sud 11, Paris, France; and
13. Paediatric Hematology and Oncology, Institute Gustave-Roussy, Villejuif, France