Christoph Bock’s team at the CeMM established a catalog of DNA methylation across 580 animal species. These data enabled a detailed dissection of the evolution of epigenetic regulation and the epigenome. The new study, published in Nature Communications, shows that the characteristic DNA methylation signatures of animal genomes are evolutionarily very old, having emerged long before the first mammals. Surprisingly, DNA methylation in starfish and sharks follows a very similar “code” as in orangutans or humans. This epigenetic code may even help protect against cancer – as indicated by DNA methylation patterns in birds, which rarely develop cancer.