1. Division of Paediatric Haematology, Oncology and Stem Cell Transplantation; Department of Paediatrics and Adolescent Medicine; University Medical Centre; Aachen Germany
2. Department of Pathology, Haematopathology Section and Lymph Node Registry; University of Kiel; Kiel Germany
3. Department of Paediatric Haematology and Oncology; NHL-BFM-Study Centre; Justus Liebig University; Giessen Germany
4. Department of Paediatric Haematology and Oncology; NHL-BFM-Study Centre; University Children's Hospital; Münster Germany
5. Department of General Paediatrics; University Medical Centre Schleswig-Holstein; Kiel Germany
6. Centre for Paediatrics and Adolescent Medicine; University Medical Centre; Freiburg Germany
7. Department of Paediatric Haematology and Oncology; St. Anna Children's Hospital; Vienna Austria
8. Department of Paediatrics and Adolescent Medicine; Medical University of Vienna; Vienna Austria
9. Department of Paediatric Haematology and Oncology; University Children's Hospital Zürich; Zürich Switzerland
10. Department of Paediatric Haematology and Oncology; Medical School Hannover; Hannover Germany