EZH2 and neoplasm: Polycomb proteins, EZH2 and SUZ12 have been implicated in CSC formation and maintenance.35,36 REST is a transcriptional repressor involved in maintaining embryonic and neural stem cell phenotypes.37 Given their roles in CSC maintenance, we would expect to see the elevated expression of these TFs in tumours with hyperactive Notch-Hedgehog signalling.