Among kinds of epigenetic drugs against GBM, histone deacetylase (HDAC) inhibitors have drawn the most attention due to its broad mechanisms including cell-cycle arrest induction, differentiation, senescence, intrinsic and extrinsic apoptosis, mitotic cell death, autophagic cell death, inhibition of angiogenesis and metastasis, generation of reactive oxygen species, and enhancement in tumor immunity 101, 102. The gene discussed is HDAC9; the disease is glioblastoma.