Chromatin signatures of active enhancers

Gene-distal cis-regulatory sequences, such as enhancers, are key contributors of tissue-specific gene expression. In particular, enhancers can be located up to hundreds of kilobases from the promoters that they control, making their identification challenging. Thanks to the recent technological advances to map histone modifications and chromatin-associated factors genome-wide, several studies have begun to characterize chromatin signatures of active enhancers. Here, we discuss some of these results and how they provide new insights into the tissue-specific organization of enhancer repertoires.