Bárdos, Saurin, Tissot et al.: "HPC3 is a new human polycomb orthologue that interacts and associates with RING1 and Bmi1 and has transcriptional repression properties." in: The Journal of biological chemistry, Vol. 275, Issue 37, pp. 28785-92, 2000 (PubMed).
Xia, Anderson, Diaz et al.: "MLL repression domain interacts with histone deacetylases, the polycomb group proteins HPC2 and BMI-1, and the corepressor C-terminal-binding protein." in: Proceedings of the National Academy of Sciences of the United States of America, Vol. 100, Issue 14, pp. 8342-7, 2003 (PubMed).