Protein coding genes only account for about 1% of the DNA sequences in the human genome. While the precise function of the remaining 99% remains largely uncharacterized, these vast stretches of “non-coding” genome are known to contain instructions for regulating gene activity in the human body’s 200+ cell types. These sequences interact with many regulatory elements — such as transcription factors, chromatin regulators, and non-coding RNAs — which together constitute the epigenome: a layer of control mechanisms and information atop the genome.
The Broad Institute’s Epigenomics Program seeks a comprehensive understanding of how these regulatory mechanisms are organized, function, and work together to specify the identities of different cell types and tissues, and how their dysregulation causes disease. Maps of these elements and their interactions provide critical insights into human genome regulation, in turn revealing new information about cell function, identity, and proliferation. As the nuances of epigenomic features and functions become clear, researchers are linking instances of epigenomic dysfunction with specific disease states, opening up new diagnostic and therapeutic opportunities.