Epigenetic marks that modify the structure of chromatin, in response to environmental factors such as diet, stress, physical activity, obesity, smoking, drugs, pesticides, intrauterine environment, hypoxia, endocrine disruptors, intestinal microbiota, inflammation, heavy metals, chemicals compounds, etc., will change the regulation of gene expression in the sense of off, deactivation or gene silencing or in the sense of on, activation or expression of the genes.