Early on in the genomics era, scientists discovered that only one percent of the genome codes for proteins, which carry out the vast array of activities in cells and tissues. Over the last 15 years, scientists have discovered that the other 99 percent, once considered “junk,” actually encodes vital information for normal cellular function. In the spaces between genes lie non-coding functional elements, which regulate gene expression, acting as knobs that control which genes are turned on, when, and by how much.
