CTCF and cancer: The constitutive CTCF binding sites were characterised by elevated mutation frequency in the pan-cancer cohort (FDR = 1.4 × 10− 71, FC = 1.18) and in ten cancer types, especially stomach, liver and oesophageal cancers as well as melanoma (FDR ≤ 10− 19, FC ≥ 1.25) (Fig. 4c,d) (Additional file 2: Table S1E).