IDH1 and astrocytic tumor: We examined the expression of GPR133 (ADGRD1) mRNA in the RNA-seq dataset of the TCGA for diffuse glioma.8,10 As shown in Supplementary Figure 2A, IDH wild-type gliomas have significantly higher amounts of GPR133 transcript than IDH mutant non-codeleted astrocytic tumors, consistent with our findings at the protein level.