1. St. Anna Kinderspital and Childrens Cancer Research Institute; Department of Pediatrics; Medical University of Vienna; Vienna Austria
2. Department of Pediatric Hematology/Oncology; Hannover Medical School; Hannover Germany
3. Children's HSCT Unit; Great North Children's Hospital; Royal Victoria Infirmary Newcastle upon Tyne United Kingdom
4. Pediatric Hematology/Oncology; Fondazione IRCCS; Policlinico San Matteo Pavia Italy
5. Great Ormond Street Hospital for Children National Health Service Trust; London; United Kingdom
6. Department of Pediatrics; Leiden University Medical Center; Leiden The Netherlands
7. Department of Pediatric Hematology, Oncology, and Hematopoietic Stem Cell Transplantation; University of Medical Sciences; Poznań Poland