1. Department of Medical Oncology, University of Ioannina, 45500 Ioannina, Greece
2. Society for Study of Clonal Heterogeneity of Neoplasia (EMEKEN), 45445 Ioannina, Greece
3. Department of Pathology, University of Ioannina, 45500 Ioannina, Greece
4. Department of Radiotherapy, University of Crete, 71003 Heraklion, Greece
5. Department of Gastroenterology, University of Ioannina, 45500 Ioannina, Greece