CTCF plays a vital role in chromatin structure and function. CTCF is 
ubiquitously expressed and plays diverse roles in gene regulation, imprinting, 
insulation, intra/interchromosomal interactions, nuclear compartmentalisation, 
and alternative splicing. CTCF has a single paralogue, the testes-specific 
CTCF-like gene (CTCFL)/BORIS. CTCF and BORIS can be deregulated in cancer. The 
tumour suppressor gene CTCF can be mutated or deleted in cancer, or CTCF DNA 
binding can be altered by epigenetic changes. BORIS is aberrantly expressed 
frequently in cancer, leading some to propose a pro-tumourigenic role for BORIS. 
However, BORIS can inhibit cell proliferation, and is mutated in cancer 
similarly to CTCF suggesting BORIS activation in cancer may be due to global 
genetic or epigenetic changes typical of malignant transformation.