Transcriptional repressor of HOXB13 gene. Interacts with YY1. Interacts with methylated histones H3K9me2 and H4K20me2 (By similarity). Expressed in testis and, at much lower levels, in ovary. Overall, expression is high in extraembryonic tissues, and low in somatic tissues. Expression starts between 8-cell and blastocyst stages. At 7.5 dpc, highly expressed in the ectoplacental cone and, at much lower levels, in the embryonic and extraembryonic ectoderm. At 14.5 dpc, highly expressed in placenta and, at much lower levels, in the yolk sac. Expression in other tissues, including brain, heart, liver, kidney, gut and genital ridges, is very low. Expressed preferentially from the paternal allele in blastocysts, in various tissues at 7.5 dpc, as well as in yolk sac and placenta at 11.5 and 14.5 dpc. Biallelically expressed in brain and other somatic tissues at 11.5 and 14.5 dpc. Imprinted gene expressed from the paternal allele in blastocysts and in embryonic tissues early in development. Imprinting is lost in somatic tissues after 7.5 dpc. Incomplete sequence. Extended N-terminus.