Found this at New Scientist (it's all the Y chromosomes guys).....
http://www.newscientist.com/article...RSS|NSNS|2012-GLOBAL|online-news#.VIC0ltKsWbs
Here's another reason for men to quit smoking. Aside from the well-known dramatic increase it causes in the [FONT=arial, sans-serif] risk of lung cancer[/FONT], smoking has now been found to obliterate a chromosome in blood cells that could offer vital protection against cancer growth elsewhere in the body........
.......The good news, however, is that Y chromosome levels in former smokers were the same as those in non-smokers. "The most important message is that this is reversible, so when you stop smoking, you no longer have the increased accumulation of cells that lose the Y chromosome"
http://www.newscientist.com/article...RSS|NSNS|2012-GLOBAL|online-news#.VIC0ltKsWbs