PRC1 and colorectal carcinoma: We have recently shown that CBX4 impairs colorectal carcinoma (CRC) metastasis by inhibiting Runx2 transcription via recruiting HDAC3 to the Runx2 promoter, and this function of CBX4 is neither dependent on its SUMO E3 ligase, its chromodomain, nor the PRC1 complex12.