We randomly sampled 100,000 genomic regions of 401 bp that were distal to TSSs and exons of known genes (same as the filtering procedure described above for bidirectionally transcribed loci). These were further filtered to not overlap with our set of 43,011 predicted enhancers, which yielded 98,942 random genomic regions whose expression levels were quantified and normalized in the same manner as described for bidirectional loci (above).
