After confirming the specificity of a newly developed anti-TERT monoclonal antibody TMab-6, we performed immunohistochemical staining on sections of nonneoplastic adult human cerebral tissues and all glioma samples including IDH-mutated astrocytoma, oligodendroglioma, IDH-wildtype GBM, and IDH-wildtype diffuse astrocytoma and examined the staining patterns of TERT protein in them. Here, IDH1 is linked to central nervous system cancer.