Indeed, total IDH1 (IDH1wt and IDH1R132H) protein levels were higher in mIDH cell lines when compared to wtIDH cells (Fig. 4c) and IDH1 and IDH2 expression was highest in PDGFRA+ tumor cells, which are the majority of glioma cells in mIDH tumors and a small percentage of GSCs in wtIDH tumors (Fig. 4d; Fig. S5a). Here, IDH1 is linked to glioma.