TERT and glioblastoma: While telomere maintenance in the vast majority of glioblastomas is driven by one of two hotspot substitution mutations (c.-124C > T or c.-146C > T) in the promoter region of TERT [26], only one of the de novo RRD glioblastomas (1/9, 11%) had TERT promoter mutation or other TERT alteration, in contrast to 93% (418/450) of the 450 conventional glioblastomas.