This image shows a DNA computer simulation. DNA carries out its activities "diluted" in the cell nucleus. In this state it synthesises proteins and, even though it looks like a messy tangle of thread, in actual fact its structure is governed by precise rules that are important for it to carry out its functions. Biologists have studied DNA by observing it experimentally with a variety of techniques, which have only recently been supplemented by research in silico, that is to say, the study of DNA by means of computer simulations. This is a recent area of study, but it has already given a major contribution to knowledge in this field. Angelo Rosa, a theoretical physicist of the International School for Advanced Studies (SISSA) in Trieste, with the collaboration of Christophe Zimmer, an experimental physicist from the Pasteur Institute in Paris has assessed the state of the art of this novel but powerful approach in a systematic review that has just been published in the journal International Review of Cell and Molecular Biology.