1. Pediatric Oncology and Hematology Children's Hospital Medical Center University Clinics Homburg Germany
2. Division for Pediatric Hematology and Oncology Hospital for Children and Adolescents University Hospital Goethe University Frankfurt am Main Frankfurt Germany
3. Department of Pediatric Hematology and Oncology University Children's Hospital Muenster Muenster Germany
4. Department of Pediatric Oncology Hematology and Clinical Immunology University of Duesseldorf Duesseldorf Germany
5. Pediatric Hematology/Oncology Department of Pediatrics Inselspital Bern University Hospital University of Bern Bern Switzerland