Together with Prof Haick group at the Technion Inst (Israel), the investigators data shows that there is a relation between the VOCs patterns of NSCLC and control cell lines and equivalent states in exhaled breath. The investigators demonstrated that there is a clear discrimination between the lung cancer and the healthy clusters . The investigators also analyzed the headspace of NSCLC and SCLC cell lines and the investigators could discriminate significantly between SCLC versus NSCLC based on their VOCs patterns. This analysis allowed us to identify the specific VOCs consumed or omitted by cancerous cells. Therefore, a non-invasive and highly sensitive test would be extremely valuable for the classification and early screening of lung cancer and for targeted therapy. In this study, the investigators will monitor the VOC pattern of patients with lung cancer as well as high risk cohort and patients under risk/evaluation for lung cancer. Likewise the investigators will monitor pts under and after therapy. In addition, the investigators will compare teh breath signature to other biomarkers of lung cancer, like circulating tumor cells and others.