CDK4 and glioblastoma: The best‐characterised genetic lesions involved in glioblastoma pathogenesis are summarised in the 2021 WHO classification of tumours of the central nervous system (CNS): deletions or inactivation of TP53, PTEN, NF1, and CDKN2A/B; amplification of CDK4/6, EGFR, and PDGFRA; mutations of the TERT promoter and copy number changes at chromosome 7 (amplifications) and 10 (deletions) [5].