IDH1 and glioblastoma: Among the genes that are mutated between 5 to 20% in TCGA GBM tumor samples [8, 9], we found mutations in NF1, SPTA1, TCHH and ATRX genes, although, the other genes like PIK3R1, PIK3CA, RB1, IDH1 and KEL were not mutated in any cell line (Figure 3A).