Inclusion of IDH mutant GBMs and LGGs did not alter the classification of IDH WT GBM tumors (Supplementary Fig. 2a): the two IDH mutant GBMs were classified with GPC2 tumors, and the nine LGGs were significantly associated with GPC2 tumors (χ2 test P = 0.0029). Here, IDH1 is linked to glioblastoma.