Loss or inactivation of TET enzymes and deregulation of 5hmC are emerging as critical determinants of the CSC and tumor phenotypes.47,48 Despite TET2 not being often mutated in gliomas,17 recent studies show frequent TET2 downregulation.49 Chen et al. show that there is a negative correlation between TET2 expression and glioma grade and provide evidence using non-stem-like cell GBM models that this repression is mediated by Zinc finger E‐box‐binding homeobox 1 (ZEB1),49 indicating that loss of TET2 regulates oncogenic event in gliomas. This evidence concerns the gene ZEB1 and glioblastoma.