IDH1 and central nervous system cancer: As described above, based on the finding that CDKN2A deletion affects the prognosis more strongly than IDH1/2 mutation in CNS WHO grade 4 glioma, the cohorts were divided into three subgroups as follows: if there is CDKN2A deletion regardless of IDH1/2 mutation, it is classified as the ‘high risk group’, if there is no CDKN2A deletion with the IDH1/2 wildtype, it is classified as the ‘intermediate risk group’, and if there is no CDKN2A deletion with IDH1/2 mutation, it is classified as the ‘low risk group’ (Supplementary Figure S5A).