While efforts have been made to phenotypically and molecularly characterize GBM tumors and illuminate the surrounding stromal elements influencing gliomagenesis, few cell-intrinsic factors beyond isocitrate dehydrogenase (IDH) mutation and O6-methylguanine-DNA methyltransferase (MGMT) promoter methylation have proven effective at stratifying patient outcome and guiding clinical care (5). The gene discussed is IDH3A; the disease is glioblastoma.