1. Non-Hodgkin Lymphoma Berlin-Frankfurt-Münster Group Study Center and Department of Pediatric Hematology and Oncology, Justus Liebig University, Giessen, Germany;
2. Department of Internal Medicine V, Justus Liebig University, Giessen, Germany;
3. Department of Pathology, Hematopathology Section and Lymph Node Registry, Christian-Albrechts-University Kiel and University Hospital Schleswig-Holstein, Campus Kiel, Kiel, Germany;
4. Department of Pediatric Hematology and Oncology, Children’s University Hospital, Zurich, Switzerland;
5. Department of Bone Marrow Transplantation and Childhood Oncology and Hematology, Medical University of Wroclaw, Wroclaw, Poland;
6. Department of Pediatric Hematology and Oncology, St. Anna Children’s Hospital, Medical University of Vienna, Vienna, Austria;
7. Clinic of Pediatric Hematology and Oncology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany; and
8. NHL-BFM Study Center and Department of Pediatric Hematology and Oncology, University Children’s Hospital, Münster, Germany