CTCF and cancer: This result suggests that the primary DNA sequence context within and in the vicinity of 2xCTS-bearing peaks serves as a major determinant of genomic DNA occupancy by CTCF homodimers in normal BORIS-negative somatic cells and also targets replacement of CTCF homodimers BORIS-positive germ or cancer cells with CTCF&BORIS heterodimers and, less often, with BORIS-only homodimers.