In addition, there is debate as to the true impact of isolated TERT promoter mutations (those occurring without the traditional histologic features of glioblastoma, EGFR amplification, or + 7/− 10), particularly in tumors with grade 2 histology, suggesting that part of the effect of TERT promoter mutation may be due to their frequent co-occurrence with EGFR amplification, + 7/− 10, and/or more aggressive histologic features [8, 37, 44, 95]. This evidence concerns the gene EGFR and glioblastoma.