HDAC6 and glioblastoma: In addition to the reversion of malignancy induced by HDAC6 depletion, alteration in the sensitivity of GBM cells to TMZ is triggered by not only HDAC6 depletion but also deactivation of the SHH pathway due to the loss of cilia, leading to a reduction in the MGMT level and DNA repairing ability (39, 40).