IDH1 and neoplasm: Similarly, multivariate analysis showed that WHO grade IV (p = 0.001), SVZ involvement (p = 0.01), tumor-SVZ distance from 0 to 10 mm (p = 0.03), GTR (p = 0.05), chemotherapy (p = 0.003), and IDH1 mutation (p = 0.01) served as independent predictors for patient OS.