Multiprotein complexes involving products of the polycomb group (PcG) genes which were initially identified as regulators of homeotic genes in Drosophila and are implicated in regulation of stem cell self-renewal and in cancer development. The PcG complexes are mostly associated with heterochromatin, where they inhibit gene expression by histone modification. There are numerous human polycomb group homologues and at least two distinct sets of complexes, PRC1 and PRC2. See AEBP2; EED; EZH; PCGF; PHC; retinoblastoma-binding protein-4; SUZ12.
Subjects: Medicine and Health.