Component of a Polycomb group (PcG) multiprotein PRC1-like complex, a complex class required to maintain the transcriptionally repressive state of many genes, including Hox genes, throughout development (PubMed:21282530). PcG PRC1 complex acts via chromatin remodeling and modification of histones; it mediates monoubiquitination of histone H2A 'Lys-119', rendering chromatin heritably changed in its expressibility (PubMed:21282530). Binds to histone H3 trimethylated at 'Lys-9' (H3K9me3) or at 'Lys-27' (H3K27me3) (By similarity). Plays a role in the lineage differentiation of the germ layers in embryonic development (By similarity). Involved in sexual development, acting as activator of NR5A1 expression (PubMed:19361780). Component of a PRC1-like complex (PubMed:12167701, PubMed:19636380, PubMed:21282530). The composition of the PRC1 complex may differ between the PRC1 complex in pluripotent embryonic stem cells containing RNF2, CBX7 and PCGF2, and the PRC1 complex in differentiating cells containing RNF2, CBX2, CBX4 and BMI1 (By similarity). May interact with H3C15, H3C1 and RNF2 (PubMed:18927235). Interacts (via chromodomain) with histone H3K9Me3 and H3K27me3 (By similarity). Localized in distinct foci on chromatin and in chromocenters. Localizes to the inactive X chromosome. Seems to be recruited to H3K27me3, H3K9ac and H3K3me2 sites on chromatin. Expressed during interphase and metaphase. The disease is caused by variants affecting the gene represented in this entry. The human orthologuous proteins of Drosophila Polycomb group protein Pc, CBX2, CBX4, CBX6, CBX7 and CBX8, show distinct nuclear localizations, contribute differently to transcriptional repression, and appear to be part of distinct PRC1-like protein complexes. The hPRC-H complex purification reported by PubMed:12167701 probably presents a mixture of different complexes.