IDH2 and central nervous system cancer: Based on the presence or absence of the two tumor markers, these gliomas were divided into four groups: IDH and TERTp mutations (17/59, 28.8%), IDH mutations only (4/59, 6.8%), IDH and TERTp wild type (14/59, 23.7%), and TERTp mutations only (24/59, 40.7%) (Table 2, Figure 1).