Preclinical studies determined that the specific inhibition of mutant IDH1 using different small molecule compounds resulted in prolonged survival of xenografted mice bearing patient-derived gliomas.16,17 Conversely, the expression of IDH1R132H markedly decreased proliferation in an IDH1 wild-type (WT) glioblastoma cell line in vitro and, upon stereotactic injection in mice, prolonged survival of tumor-bearing mice in vivo.18 Moreover, potent antitumor effects mediated by 2-HG, directly contradicting its often-cited role as an oncometabolite, have been reported in a leukemic mouse model.19 This evidence concerns the gene IDH1 and central nervous system cancer.