Charité - Universitätsmedizin Berlin - Department of Paediatric Oncology and Haematology, Charité - Universitätsmedizin Berlin - Department of Paediatric Oncology and Haematology, Charité - Universitätsmedizin Berlin - Department of Paediatric Oncology and Haematology, Charité - Universitätsmedizin Berlin - Department of Paediatric Oncology and Haematology, Charité - Universitätsmedizin Berlin - Department of Paediatric Oncology and Haematology, Goethe University Frankfurt - University Hospital Frankfurt, Heinrich Heine University Dusseldorf - Faculty of Medicine, University of Kiel - University Medical Center, University of Hamburg - Clinic of Pediatric Hematology and Oncology, Medical University of Vienna, Charité - Universitätsmedizin Berlin - Department of Paediatric Oncology and Haematology, University Hospital Motol, Medical University of Vienna, University of Zurich, Medical University of Vienna, Charité - Universitätsmedizin Berlin - Department of Paediatric Oncology and Haematology and Charité - Universitätsmedizin Berlin - Department of Paediatric Oncology and Haematology