Telomerase reverse transcriptase promoter (TERTp, HGNC:11730) mutations are frequent in multiple tumor types [11], and are present in 70–80% of glioblastomas and around 80% of oligodendrogliomas, where they always co-occur with IDH1/2 mutations [11,12,13]. This evidence concerns the gene IDH1 and glioblastoma.