The objective is to study the phenotypic, functional and metabolomic characteristics of neutrophils circulating subpopulations in lung cancer patients, and to compare them to a control group of healthy volunteers. A blood sample will be taken before the first treatment session for the lung cancer patient and a second blood sample will be taken during the first evaluation visit. The investigators hypothesize that there may be different circulating neutrophil subpopulations in patients with metastatic non-small cell lung cancer (NSCLC) involved in tumor progression and resistance to immunotherapy.