Smokers: the formers versus the nevers.
D005260:Female; D006801:Humans; D008136:Longevity; D008175:Lung Neoplasms / Q000453:epidemiology; D008297:Male; D029424:Pulmonary Disease, Chronic Obstructive / Q000453:epidemiology; D012737:Sex Factors; D012907:Smoking / Q000453:epidemiology; D016540:Smoking Cessation / Q000379:methods*; D000074606:Smoking Prevention