Exposomics: mathematics meets biology

Although 'exposome' research has started to appear, and the concept is fascinating, we still have little proof-of-principle. This issue of Mutagenesis reports a few examples of exposome research, showing that the approach is providing the first results. In this Commentary, I develop the example of epigenome-wide methylation studies related to smoking as a success story, that fits well with previous research in humans and in vitro on mechanisms of carcinogenesis, and also with conceptual models such as Cairns' model based on asymmetric division of stem cells. The field of exposomics merges different disciplines, notably biology and mathematics, but also the evolutionary theory, and can possibly lead to interesting breakthroughs in the next years.