Comparisons of DNase Hypersensitive Site (DHS) signals among L1 flanking regions and control.The figure illustrates the distribution of one genomic feature (DHS) surrounding de novo, polymorphic, human-specific L1s, and control regions. The X-axis indicates the position of L1 flanking regions (in kb from L1 insertion site), and the Y-axis shows the average number of DHS sites in each 1-kb window.