RBBP4 and neoplasm: Mechanistical studies show that ARMC12 physically interacts with retinoblastoma binding protein 4 (RBBP4) to facilitate the formation of polycomb repressive complex 2 (PRC2) and increase the histone methyltransferase activity of enhancer of zeste 2 polycomb repressive complex 2 subunit (EZH2), resulting in transcriptional repression of tumor suppressive genes.