PHC2 is a 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. The PcG PRC1 complex acts via chromatin remodeling and modification of histones; it mediates monoubiquitination of lysine 119 on histone H2A, rendering chromatin heritably changed in its expressibility.