1. Division of Hematology-Oncology and Stem Cell Transplantation; Children's Hospital, University of Helsinki and Helsinki University Hospital; Helsinki Finland
2. Division of Cardiology; Children's Hospital, University of Helsinki and Helsinki University Hospital; Helsinki Finland
3. Division of Transplantation; Children's Hospital, University of Helsinki and Helsinki University Hospital; Helsinki Finland
4. Department of Women's and Children's Health; Karolinska Institute and University Hospital; Stockholm Sweden