E2F6 forms a complex with CBX3 (HP1gamma) and components of the polycomb repressor complex PRC1.6: PCGF6 (MBLR), L3MBTL2, RING1 (RING1A) or RNF2 (RING2, also known as RING2B). This polycomb repressor-like complex is named PRC1L4. Unlike the complex composed of E2F6.com-1, PRC1.6 and CBX3 (Ogawa et al. 2002), the PRC1L4 complex does not possess histone methyltransferase activity. Instead, the PRC1L4 complex may have a histone E3-ubiquitin ligase activity. The PRC1L4 complex was shown to bind to promoters of several genes: CDC7, CSTF3, MCM3, UXT, RPA2, RAD51C, RFC3, HOXC5. Of these genes, transcriptional repression was tested and demonstrated for CDC7 and UXT (Trojer et al. 2011).