The human genome has ∼55,000–65,000 CTCF binding sites, amongst which around ∼5,000 are highly conserved across species (Yusufzai et al., 2004; Chen et al., 2012; Holwerda and de Laat, 2013), though CTCF occupancy remains tissue- and cancer-specific (Hanssen et al., 2017; Debaugny and Skok, 2020). This evidence concerns the gene CTCF and cancer.