Three advantages to this system over most orthotopic patient-derived IDHmut glioma xenograft models are that it has (a) consistent, faster in vivo growth; (b) an immunocompetent microenvironment; and (c) control IDHwt cells that, aside from IDH1 R132H, are isogenic with control IDHmut glioma cells. Here, IDH1 is linked to central nervous system cancer.