title: Biologic problems of primary lung cancer.
mesh_terms: D001980:Bronchi / Q000166:cytology / Q000196:embryology*; D002283:Carcinoma, Bronchogenic / Q000473:pathology*; D002454:Cell Differentiation; D006801:Humans; D008175:Lung Neoplasms / Q000145:classification* / Q000209:etiology / Q000473:pathology / Q000601:surgery; D012907:Smoking