IDH3A and glioblastoma: By these criteria the mutation biomarker associated most strongly with increased survival was seen in IDH1 (P-value 0.001); Kaplan–Meier analysis confirmed GBM tumours with mutated IDH1 (isocitrate dehydrogenase isozyme) have better prognosis with mortality hazard ratio of 0.147 at 1000 days (P= 0.0018, by log-rank tests of Kaplan–Meier survival) (Figure 3C).