We observed significantly fewer samples with loss of p16 expression in IDH-MUT grade 4 astrocytomas relative to tumors of GBM-TS (Fisher’s exact test, P = 0.044, Supplementary Figure 1B), whereas there were no differences between the 3 groups in p53 overexpression (Fisher’s exact test, P > 0.05, Supplementary Figure 1C). This evidence concerns the gene IDH1 and glioblastoma.