Cigarette smoke as a carcinogen.
D000367:Age Factors; D000368:Aged; D000397:Air Pollution; D002273:Carcinogens; D002283:Carcinoma, Bronchogenic / Q000175:diagnosis / Q000453:epidemiology*; D006801:Humans; D008175:Lung Neoplasms / Q000175:diagnosis / Q000453:epidemiology*; D008297:Male; D008875:Middle Aged; D012906:Smoke; D012907:Smoking; D013997:Time Factors
D002273:Carcinogens; D012906:Smoke