MED12 and cancer: Cancer genome sequencing studies have reported mutations or alterations in the RNA transcription machinery components contained in MED subunits, and correlations between some of these changes in MED subunits, (MED1, MED12, MED19, MED23, MED28, CDK8, and cyclin C) and cancer progression have been reported for various cancers, although mechanisms responsible for these correlations are unknown [17].