[url=http://www.sciencemag.org/content/early/2014/12/03/science.1262092]Published in Science[/url]. [quote]Tobacco smoking is a risk factor for numerous disorders, including cancers affecting organs outside the respiratory tract. Epidemiological data suggest that smoking is a greater risk factor for these cancers in males compared to females. This observation, together with the fact that males have a higher incidence of and mortality from most non–sex-specific cancers, remains unexplained. Loss of chromosome Y (LOY) in blood cells is associated with increased risk of nonhematological tumors. We demonstrate here that smoking is associated with LOY in blood cells in three independent cohorts [TwinGene: odds ratio (OR) = 4.3, 95% CI = 2.8–6.7; ULSAM: OR = 2.4, 95% CI = 1.6–3.6; and PIVUS: OR = 3.5, 95% CI = 1.4–8.4] encompassing a total of 6014 men. The data also suggest that smoking has a transient and dose-dependent mutagenic effect on LOY status. The finding that smoking induces LOY thus links a preventable risk factor with the most common acquired human mutation[url=https://xkcd.com/54/].[/url][/quote]