The implications of attributing health and diseases more to "nature" (genes) or "nurture" (the environment) have been debated for a long time. Although considerable advancements have been made both in theoretical clarification of concepts, and in the study of the origins of disease, there is still much confusion, for example, in the press and in the beliefs of the population. There is a large consensus, among scientists, that only a small fraction of diseases is due to genes in the usual meaning, that is, according to mendelian inheritance (say around 5% of all diseases), whereas the vast majority of cases are due to environmental exposures or to "gene-environment interactions." In this article I will briefly discuss a model for gene-environment interactions, and I will recall an important discussion that took place decades ago around the mistakes related to attributing diseases or other traits to inheritance. Finally, I will describe a specific example of potential misuse of genetic information.