Vasilios Tzilas1, Demosthenes Bouros2. 1. First Academic Department of Pneumonology, Hospital for Diseases of the CHEST "SOTIRIA", Medical School, National and Kapodistrian University of Athens, Athens, 11527, Greece. 2. First Academic Department of Pneumonology, Hospital for Diseases of the CHEST "SOTIRIA", Medical School, National and Kapodistrian University of Athens, Athens, 11527, Greece. Electronic address: dbouros@med.uoa.gr.