IDH1 and glioblastoma: Based on our previous assessments of MIF as a driver of CSC/MDSC-mediated communication (21), we assessed overall MIF expression levels across brain tumors and found elevated MIF in isocitrate dehydrogenase (IDH) WT GBM patient tumor samples when compared with patients with lower-grade (IDH mutant astrocytomas and oligodendrogliomas) gliomas and normal tissue using TCGA data (Figure 1A).