1. Molecular Epidemiology and Predictive Tumor Markers Group, Ramón y Cajal Health Research Institute (IRYCIS), Carretera Colmenar Km 9100, CIBERONC, 28034 Madrid, Spain
2. 1st Department of Propaedeutic Surgery, National and Kapodistrian University of Athens, Vasilissis Sofias 114, 11527 Athens, Greece
3. Department of Molecular Oncology, Cancer Research Institute, Biomedical Research Center of the Slovak Academy of Sciences, Dubravska Cesta 9, 845-05 Bratislava, Slovakia