BORIS Background Information Brother of the regulator of imprinted sites (BORIS) is a mammalian transcription factor that is paralogous to the CCCTC-binding factor (CTCF), an ubiquitous 11 zinc finger (ZF) protein that organizes epigenetically controlled chromatin insulators that regulate imprinted genes in soma. BORIS is a 663 amino acid DNA binding protein. It is expressed at high levels in the testis and in low levels in the prostate in a mutually exclusive pattern that correlates with the re-setting of methylation marks during male germ cell differentiation. Abnormal expression of BORIS is linked to many types of cancer including breast, pro-state, ovary, gastric, liver, endometrial, glia, colon and esophagus.
