万花筒 2008-04-09&-4-10 爱抽烟，是基因的错（在线收听）

It’s one of the greatest medical mysteries. Why does a person who never smoked a single cigarette end up with lung cancer? While another person who smokes for decades remains cancer-free. The answer may be buried deep inside our genetic make-up.

 Three separate teams of researchers found a genetic variation that increases the risk of lung cancer. One team of researchers found that if you have the variant and smoke, you are also more likely to smoke more cigarettes a day than a smoker without the variant. Is this a gene that makes you smoke?

 This gene doesn’t make you more likely to begin to smoke, but if you smoke, you smoke more.

 The authors of the study disagree whether the increased risk of lung cancer is because those with the gene variation may smoke more or if it's the genetic variation itself that leads to cancer. This study is so important because we are going to be able to understand those genetic differences. And in the future then, we can do a better job of preventing those from starting to smoke and helping those who started to smoke to quit.

 Further studies of the variant could unravel more mysteries like why some people's attempt to kick the habit always ends up in smoke. For Good Morning America, Sharon Alfonce ABC news, New York.

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