IDH1 and glioblastoma: Several studies indicate that the presence of pTERT mutations are tightly linked with other biomarkers such as EGFR amplification, IDH wild type (in GBM), 1p19q co-deletion, CDKN2A deletion, chromosome 10q loss and SEL1L, suggesting evolutionary co-selection with pTERT mutations (Labussière et al. 2014a; Mellai et al. 2020; Nonoguchi et al. 2013).