CTCFL and cancer: In reality, one reason for detection of BORIS in a variety of cell lines can be related to loss of the q arm of chromosome 16 (the locus of CTCF as a suppressor of BORIS) and gain of chromosome 20q13 (the locus of BORIS) during prolonged growth of normal and cancer cell lines in culture, a phenomenon that occur throughout adaptation of hES cells to growth in culture for a long time [60, 61].