IDH1 and astrocytoma (excluding glioblastoma): Although the clustering analysis using only IDH-mutant samples (C.1–C.4) still could not clearly distinguish codel from non-codel tumors (Supplementary Fig. S1a), the futher analysis, using only C.1 and C.2 samples, did so, indicating that astrocytomas and oligodendrogliomas have their own characteristic methylation profile (Supplementary Fig. S1b).