From gene to carcinogen: a rapidly evolving field in molecular epidemiology.

Chemical and physical carcinogens leave footprints of their activities on DNA because of the patterns of base changes they induce. Additionally, the conversion of 5-methylcytosine to thymine in CpG sequences leads to a characteristic mutation which can be used to estimate the contribution of endogenous processes to human mutations. Knowledge of the pattern mutations found in genes commonly mutated in human cancer, such as the p53 tumor suppressor gene, allows for predictions to be made on the likelihood of an exogenous DNA-damaging agent being involved. Working from gene to carcinogen is likely to have a profound impact on our understanding of the origins of human cancer.