1. Pediatric Oncology and Hematology-Children's University Hospital; Erlangen Germany
2. German Childhood Cancer Registry, Institute for Medical Biostatistics, Epidemiology, and Informatics; University Medical Center; Mainz Germany
3. Clinic of Pediatrics; Dortmund Germany
4. Swabian Children's Cancer Center; Children's Hospital; Augsburg Germany
5. Department of Pediatrics; University Rheinisch-Westfälische Technische Hochschule Aachen; Aachen Germany
6. Pediatric Hematology and Oncology-Children's University Hospital; Magdeburg Germany
7. Pediatrics 5 (Oncology, Hematology, Immunology; General Pediatrics, Gastroenterology, Rheumatology); Klinikum Stuttgart-Olgahospital; Stuttgart Germany
8. Division of Pediatric Hematology and Oncology; Department of Pediatrics and Adolescent Medicine; Medical University of Graz; Graz Austria
9. Children's Hospital; Department of Pediatric Oncology and Hematology; University of Cologne; Cologne Germany
10. Pediatric Oncology and Hematology; Saarland University Hospital; Homburg Germany
11. Department of Pediatric Surgery; University of Munich; Munich Germany