In some gliomas, inhibition of EZH2 may reduce cell proliferation, possibly by de-repressing Ink4a/Arf. However, in other gliomas, loss of EZH2 function could lead to the aberrant expression of factors such as OLIG2, which can drive tumorogenesis (Ligon et al., 2007). The gene discussed is OLIG2; the disease is glioma.