RPol II binding fragments surrounding TSSs of protein coding genes and bidrectional gene pairs in Hela cells. (A) ChIP-Seq-derived RPol II binding pattern around the TSS of protein coding gene. Protein-coding genes (n = 6802) whose transcript lengths are > 10,000-bp and no other genes are present within 10,000-bp of their TSS were separated into 4 groups, based upon their expression levels, which were measured using microarray experiments. (B) ChIP-Seq-derived RPol II binding pattern around theTSSs of bidrectional gene pairs. The gene pairs were separated into 5 groups, based on the distance between 2 opposite genes.