1. Department of Pediatric Hematology and Oncology Collegium Medicum Nicolaus Copernicus University Torun Bydgoszcz Poland
2. Department of Pediatric Surgery Collegium Medicum Nicolaus Copernicus University Torun Bydgoszcz Poland
3. Department of Pediatric Stem Cell Transplantation, Hematology and Oncology Medical University Wroclaw Poland
4. Department of Pediatric Hematology and Oncology Medical University Warszawa Poland
5. Department of Pediatric Oncology, Hematology and Transplantology University of Medical Sciences Poznan Poland
6. Department of Oncology Children's Memorial Health Institute Warszawa Poland
7. Department of Microbiology Collegium Medicum Nicolaus Copernicus University Torun Bydgoszcz Poland
8. Department of Pediatric Oncology and Hematology University Children's Hospital Jagiellonian University Collegium Medicum Krakow Poland
9. Department of Pediatrics, Hematology and Oncology Medical University Gdansk Poland
10. Department of Pediatric Hemato‐Oncology and Gastroenterology Pomeranian Medical University Szczecin Poland
11. Department of Pediatric Oncology Pomeranian Medical University Szczecin Poland
12. Department of Pediatric Hematology and Oncology Silesian Medical University Zabrze Poland
13. Department of Pediatric Oncology and Hematology Medical University Bialystok Poland
14. Department of Pediatric Oncology, Hematology and Diabetology Medical University Lodz Poland
15. Division of Pediatric Hematology and Oncology Chorzow Pediatric and Oncology Center Chorzow Poland
16. Division of Pediatric Hematology and Oncology Children Hospital Olsztyn Poland
17. Division of Pediatric Hematology and Oncology Children Hospital Kielce Poland
18. Division of Pediatric Oncology, Hematology and Chemotherapy Department of Pediatric Silesian Medical University Katowice Poland
19. Department of Pediatric Hematology, Oncology and Stem Cell Transplantation Medical University Lublin Poland
20. Stem Cell Transplant Center Department of Clinical Immunology and Transplantology University Children's Hospital Jagiellonian University Collegium Medicum Krakow Poland
21. Department of Pediatric Oncohematology University Rzeszów Rzeszów Poland
22. Department of Hematology and Transplantology University of Medical Sciences Poznan Poland