1. Child Health Department, University of Ioannina Medical School, Ioannina, Greece.
2. Department of Medical Oncology, Imperial College School of Medicine, Charing Cross Hospital, London, United Kingdom.
3. Department of Haematology, University Hospital of Ioannina, Ioannina, Greece.
4. Department of Paediatrics, University Hospital of Crete, Heraklion, Greece.