IDH1 and glioblastoma: More interestingly, recent evidence has shown that glioblastoma multiforme (GBM) with different isocitrate dehydrogenase 1 mutation (IDH1) statuses, vascular endothelial growth factor (VEGF) expression levels, molecular subtypes could also harbor a spatial localization preference,5, 6, 7 suggesting that certain characteristics of tumors could be reflected in their anatomical location.