TERT and glioblastoma: Additionally, we found a high percentage of GBMs presenting either the mutation -124:G > A (52.6%) or -146:G > A (21.1%), which shows the importance of this mutation to GBM development, since it constitutively activates the TERT gene, supporting the maintenance of genomic integrity through telomere elongation (Heidenreich et al. 2014; Walsh et al. 2015).