IDH1 and glioma: We then investigated and validated the predictive value of these DNA methylation-based biomarkers in an independent cohort of 271 TCGA and non-TCGA primary gliomas previously classified in Ceccarelli et al. (2016) as IDH mutant non-Codel G-CIMP-high (n = 250) and IDH mutant non-Codel G-CIMP-low (n = 21).