A new regulator for heart formation has been discovered by studying how embryonic stem cells adjust the packaging of their DNA. This approach to finding genetic regulators may have the power to provide insight into the development of any tissue in the body – liver, brain, blood and so on. The impetus for learning how stem cells turn into heart muscle cells was to further research on repairing damaged hearts through tissue regeneration. The work also holds promise for understanding congenital heart defects.