1. Third Department of Medical Oncology, General Oncology Hospital of Kifissia ``AgioiAnargyroi'', Athens, Greece
2. First Department of Propaedeutic Surgery, School of Medicine, University of Athens, Athens, Greece
3. Department of Basic Medical Sciences, Laboratory of Biology, School of Medicine, University of Athens, Athens, Greece
4. Second Department of Internal Medicine, School of Medicine, University of Athens, Athens, Greece