TERT and diffuse astrocytoma: It has been reported that DNA hypermethylation of the TERT promoter is associated with TERT upregulation in pediatric brain tumors [8] and other tumors [39], and histone acetylation at the TERT promoter regions may also be relevant to its expression [9]. IDH-mutant diffuse astrocytic tumors often demonstrate the glioma-CpG island methylator phenotype (G-CIMP) [40, 41], and the nuclear TERT staining in diffuse astrocytomas might be epigenetically caused by hypermethylation of the TERT promoter [10].