IDH1 and central nervous system cancer: In this study, hTERT promoter mutations were detected in 85% of 1p19q codeleted, IDH mutant glioma samples or WHO 2016 classified oligodendrogliomas, which confirms previous studies that have observed a high frequency of hTERT promoter mutations in oligodendroglial tumors.9,11 This suggests that in most IDH mutant gliomas, the presence of hTERT promoter mutations could perform as a surrogate for 1p19q codeletion when diagnosing oligodendrogliomas.