GPT and glioblastoma: In contrast, ATRX gene mutations were enriched in low telomerase activity groups in LGG (104 in low vs. 7 in high), SARC (24-low vs. 13-high), and GBM (6-low vs. 2-high) (FDR < 0.01; Fisher’s exact test; 95 % CI; Fig. 2e) consistent with the presence of ALT phenotypes.