STAT3-low tumors, in contrast, comprise mostly of low-grade gliomas (LGGs), and the proneural molecular subtype with enrichment of 1p/19q co-deletion and IDH-Mut (mutant) status, representing tumors of better prognosis and responsiveness to current chemotherapy (Fig. 1b, and additional clinical database TCGA, Supplementary Fig. 2a)20. The gene discussed is IDH1; the disease is central nervous system cancer.