Moreover, approximately 30% of pediatric high grade gliomas (pedHGG) including GBM and DIPG harbor a lysine 27 mutation (K27M) in histone 3.3 (H3.3) which is correlated with poor outcome and was shown to influence EZH2 function.The present study investigated the correlation of expression of EZH2 and other PRC2 genes (EZH1, SUZ12, EED) with overall survival of pediatric GBM patients and the cytotoxic impact of EZH2 inhibition by the novel agent Tazemetostat in pediatric GBM/DIPG cells harboring either a H3.3 mutation or a H3 wildtype.EZH2 gene expression does not c