PET/CT(MRI) with [18F]TFAHA may identify GBMs with high levels of HDACs class IIa expression-activity which could be treated with a combination of Tasquinimod (HDAC4 allosteric inhibitor) plus TMZ and radiation, and may potentially improve the outcome of chemo-radiation therapy and to prolong the overall survival of patients with GBM. This evidence concerns the gene HDAC4 and glioblastoma.