If we consider the genome as a map, the epigenome could be represented as the landscape contour lines. When we plan to travel from one point to another, the straight line might seem the fastest route. However, when we take into account the gradient information, we realize that not all routes are feasible, and that the straight line does not always mean closer or faster.

By analyzing these contour lines we gain full access to a new layer of information linking the genes encoded in the DNA with the environment: the epigenome. Moreover, the epigenome is shaped by our life history, constituting a dynamic registry of age and the interaction with the environment, including diet, diseases and exposure to harmful agents. Being able to analyze the tracks of this interaction we are in a privilege position to make true precision medicine.