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