CTCF and BORIS bound regions enriched at the anchors of cell-type specific transcriptional loops in K562 cells compared with MCF7 cells. a Heatmap shows the enrichment of BORIS, CTCF, and RNAPII occupancy in K562 cells at the left and right anchors of K562-specific loops. b Heatmap shows the enrichment of CTCF and RNAPII occupancy in MCF7 cells at the anchors of K562-specific loops, but the interactions mediated by CTCF were different in MCF7 cells compared with K562 cells. c Genomic view of K562-specific long-range chromatin interactions at the COMMD7-DNMT3B-MAPRE1 locus. The tracks are labeled with the molecules against which antibodies were directed in ChIP-seq in both K562 and MCF7 cells. ChIA-PET data are presented as red lines with bold anchors and summarized by brackets on the top of the gene tracks. d Model of cluster and single CTCF binding classes and their modulation by BORIS in BORIS-positive cells. The model is based on ChIP-seq and ChIA-PET data for K562 and MCF7 cells at the DNMT3B locus (c), but also observed in TP53, FOXA3, PRAME, KDM3B, MDM2, BBC3 and other loci. (PPTX 209Â kb)