Enhancers are regions of DNA that do not code for proteins, but control how genes are expressed. Super-enhancers are clusters of enhancers that together regulate genes with important roles in cell identity. Scientists at St. Jude Children’s Research Hospital studied the Vsx2 super-enhancer and its role in the development of the retina. Their assessment showed the super-enhancer has four distinct regions with different functions. This modular super-enhancer provides a way to study gene expression during development. A paper on the work was published today in Nature Communications.