Table 1.

Total CTCF binding sites in various classes of ChIP-seq loci

Class name	Number of cell lines		Total binding sites
	Required	Available
Any CTCF	Any	56	458,251
CTCF in one cell line	1	56	241,300
cCTCF1	≥51	56	23,709
cRad211	6	6	22,055
cSmc31	4	4	16,704
cCTCF/cRad21	≥51/6	56/6	16,689
cCTCF/cSmc3	≥51/4	56/4	13,261
cCTCF/cCohesin	≥51/6/4	56/6/4	12,014

¹To be declared constitutive, a site had to be identified in ≥90% of available cell lines.