The science of cancer prevention has advanced to the point where researchers now say they can detect ?cancer genes? in the breath of smokers, and can test the presence of two proteins in men they say will predict development of prostate cancer a decade in advance. All of these novel findings need much more examination, of course, but scientists at the American Association for Cancer Research?s Frontiers in Cancer Prevention Research meeting, say these examples illustrate how it is becoming increasingly possible to use genes and their protein products to help predict and diagnose cancer, as well as choose therapy that offers the most potential for a good result. These researchers will also discuss a test that can pick out patients who have pancreatic cancer – an advance that offers hope the disease can be treated at earlier stages than it is now – and how several unique genes can predict which prostate cancer or lung cancer patients will develop aggressive tumors that need additional treatment. Cancer is a disease of genes, they say, so genes can be employed as a crystal ball to thwart the disease.