TERT and glioblastoma: TERT mutations are observed in 80% of wild-type isocitrate dehydrogenase (IDH) GBM and are associated with poor prognosis.6 Furthermore, TERT promoter mutations can induce high transcriptional activity under hypoxic and TMZ-treated conditions.7 In contrast, when TERT is inactivated, GBM cells show a shortening of telomeres and the formation of chromatin bridges, losing their ability to proliferate.8