Fact
Cigarette smokers are 20 times more likely to develop lung cancer than non-smokers.
Source 1:
"The Health Consequences of Smoking—50 Years of Progress. Surgeon General's Report." U.S. Department of Health and Human Services, Centers for Disease Control and Prevention, National Center for Chronic Disease Prevention and Health Promotion, Office on Smoking and Health. Cancer, 2014: 9. Report.