University of Duisburg-Essen - University Hospital Essen, University of Duisburg-Essen - University Hospital Essen, University of Münster, University of Duisburg-Essen - University Hospital Essen, University of Duisburg-Essen - University Hospital Essen, Charité Universitätsmedizin Berlin - Department of Pediatric Oncology and Hematology, University of Duisburg-Essen - University Hospital Essen, University of Duisburg-Essen - University Hospital Essen, University of Duisburg-Essen - University Hospital Essen, University of Duisburg-Essen - University Hospital Essen, University Children's Hospital Zürich, University of Duisburg-Essen - University Hospital Essen, University of Duisburg-Essen - University Hospital Essen, Charité Universitätsmedizin Berlin - Department of Pediatric Oncology and Hematology, University of Tübingen - Department of Pediatric Oncology and Hematology, University of Duisburg-Essen - University Hospital Essen, Charité Universitätsmedizin Berlin - Department of Pediatric Oncology and Hematology, University of Tübingen, Medical University of Graz, University of Tübingen - Department of Pediatric Oncology and Hematology, Charité Universitätsmedizin Berlin - Department of Pediatric Oncology and Hematology, University of Duisburg-Essen - University Hospital Essen, Medical University of Graz, University of Duisburg-Essen - University Hospital Essen, University of Duisburg-Essen - University Hospital Essen, University of Duisburg-Essen - University Hospital Essen, University of Duisburg-Essen - University Hospital Essen and University of Duisburg-Essen - Department of Paediatrics I