Notably, the C2 subtype showed the highest mutation rates for certain genes: IDH1 (16% in C2, representing 88% of patients among all GBM cases), TP53 (57%, corresponding to 45% in all GBM), and EGFR (39%, corresponding to 36% in all GBM) (Figure 4A). The gene discussed is IDH1; the disease is glioblastoma.