TERT and neoplasm: The fifth edition of the WHO classification of tumours of the CNS, published in 2021, further revised the GB definition as an IDH wild-type tumour presenting one or more of the following three genetic parameters: telomerase reverse transcriptase (TERT) promoter mutation, epidermal growth factor receptor (EGFR) gene amplification and combined gain of entire chromosome 7 and loss of entire chromosome 10 [2].