HDAC9 and glioblastoma: Entinostat, the lone benzamide HDAC inhibitor, has been shown as a promising compound in the treatment of glioblastoma through its ability to significantly reduce cell growth, upregulate the cell cycle inhibitor p21Waf1/Cip1 and induce cell cycle arrest in the G0/G1 phase, and induce apoptotic cell death in glioblastoma cell lines[71].