IDH1 and glioblastoma: Due to the multiregional and microenvironmental heterogeneity in GBM,19 the high prognostic and predictive value of multiregional radiomics model from multiparametric MRI has been widely recognized.20, 21, 22 It is a reasonable hypothesis that imaging features from multiple tumor subregions could have the best accuracy in predicting IDH1 mutation than those from single subregion.