Combinations of histone methylation and acetylation inhibitors, such as BIX01294 (G9a inhibitor), DZNep (EZH2 inhibitor), TSA (HDAC inhibitor), and RG-108 (DNMT inhibitor, DNMTi), hold promise for targeting GBM cells while sparing normal stem cells. Here, HDAC9 is linked to glioblastoma.