Ling and Alex’s paper about the factors that determine the evolutionary conservation of enhancer activity across species has been published in Genome Biology and Evolution! We studied maps of liver enhancers across 20 mammalian species and found that enhancers with conserved activity have higher regulatory potential, are active in more contexts, and regulate more genes than enhancers that are not conserved. This argues that pleiotropy is associated with the conservation of regulatory regions across mammalian evolution.