This gene encodes a core component of the polycomb repressive complex 2 (PRC2) that also includes, at least, embryonic ectoderm development protein (EED) and enhancer of zeste homolog 1 or 2 (EZH1 or EZH2). Through the methyltransferase activity of EZH1 or EZH2, the PRC2 complex methylates Lys9 and Lys27 of histone 3 and Lys26 of histone 1, leading to recruitment of the PRC1 complex, histone 2A ubiquitylation and transcriptional repression of the target genes. This gene product is essential for the activity and integrity of the PRC2 complex, and is required for X chromosome inactivation, stem cell maintenance and differentiation. Two transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Jul 2009]