By measuring the enzymatic activity of telomerase and detecting extrachromosomal telomeric DNA C-circles in glioma tissue samples, we determined that 38.8% of gliomas showed neither telomerase activation nor ALT, while a minor subset of gliomas (9.5%) harbored both telomerase activation and ALT simultaneously (i.e., “both”). The gene discussed is GPT; the disease is central nervous system cancer.