Researchers reported at the American Association for Cancer Research (AACR) annual meeting in Denver that high levels of certain carcinogens in the urine are predictive of lung cancer in the future. NNAL, or 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol), is a metabolite of NNK, or 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone) found in urine. Both of these chemicals have been known to cause cancer in animals. Dr. Jian-Min Yuan of the University of Minnesota in Minneapolis has reported that NNK exposure leads to lung cancer development in humans and that furthermore; these levels can be tracked through urinalysis specimens. Dr. Yuan has found that those with the heaviest levels of NNAL in urine were 8.5 times as likely to develop lung cancer. Ongoing research on the issue hopes to shed some light on the interactions of carcinogen detection and cancer.