Gliomas with unmethylated and methylated MGMT promoters had similar ascorbate levels (average ascorbate levels of 0.42 ± 0.30 nmol/μg/DNA and 0.45 ± 0.34 nmol/μg/DNA, respectively, t test p = 0.96; Fig. 4b), and this remained when gliomas with low and high apparent methylation levels were assessed separately (ANOVA p = 0.84; Supplementary Fig. 5). The gene discussed is MGMT; the disease is central nervous system cancer.