Mapping TCDD-induced AhR enriched regions (FDR < 0.01) with DRE locations. Regions of enrichment identified in the intergenic (purple) and intragenic (blue) DNA regions of the genome at 2 hrs (A) and 24 hrs (B) were searched for high scoring (putative functional) DRE sequences (matrix similarity score ≥ 0.8473; dark blue and dark purple segments) and low scoring DRE sequences (matrix similarity score < 0.8473; mid blue and mid purple segments) using a position weight matrix developed from bona fide functional DREs . Light blue and light purple segments represent regions with no DRE core sequence. A total of 6,595 enriched regions (6,093 at 2 hrs and 502 at 24 hrs) contained at least one DRE core (5'-GCGTG-3'). 50% of these regions were within 135 bp of a DRE core (based on the location of maximum enrichment within the enriched region; C).