We defined gene annotations, including genes (whole transcripts including UTRs), exons, 5′ UTRs, 3′ UTRs, introns, and promoter regions, on the basis of RefSeq gene coordinates from the UCSC Genome Browser. We retained genes with at least one exon and at least one PubMed reference23 to exclude poorly studied genes, pseudogenes, and falsely identified genes. In the resulting set of 18,183 genes, we identified exons, introns, and UTRs. We defined promoter regions as the first 500 bp upstream of the TSS. We note that DHS coverage for different gene features varied: 26% for exons, 73% for promoters, 75% for 5′ UTRs, 22% for 3′ UTRs, and 20% for introns.