HDAC9 and glioblastoma: Indeed, LSD1 inhibition was recently combined with HDAC and EZH2 inhibitors in treatment strategies in acute myeloid leukemia and glioblastoma, as well as in breast and ovarian cancer (Duan et al., 2017; Huang et al., 2012; Meng et al., 2013; Singh et al., 2011; Wen et al., 2018).