Bone-marrow-derived progenitor cells (EPCS) play an important role in neovascularization and tumor growth. In lung cancer, angiogenesis is an important event in mechanisms of tumor proliferation and metastasis. Recent evidences suggest that EPCS can be recruited and differentiate in mature endothelial cells to form new blood vessels. The role of EPCs in NSCLC is unclear. In contrast, angiogenic drugs are proposed combined to systemic chemotherapy in NSCLC. The aim of this study is to identify EPCs in peripheral blood from patients with NSCLC, by comparison to Chronic Pulmonary Obstructive Disease (COPD), an inflammatory disease.