1. Pediatric Oncology Unit, Fondazione IRCCS Istituto Nazionale dei Tumori di Milano, Milano, Italy
2. Pediatric Cancer and Blood Disorders Center of Armenia, R.H. Yeolyan Hematology Center, Yerevan, Armenia
3. Yerevan State Medical University, Yerevan, Armenia
4. Histogen Armenian-German Scientific Center of Pathology, Blagoveshchensk, Amur Oblast, Russian Federation
5. Clinic of Pediatrics, Dortmund Municipal Hospital, Dortmund, Germany