EGFR and astrocytoma (excluding glioblastoma): For example, mutations in the epidermal growth factor receptor (EGFR), chromosome 7 gain and chromosome 10 loss (7 +/10-) or telomerase reverse transcriptase (TERT) mutations in IDH-wild-type astrocytomas result in an “upgrading” of histopathologically classified WHO grade 2/3 without IDH mutation to “IDH-wild-type glioblastoma WHO grade 4” (Brat et al., 2018; Louis et al., 2021; Rushing, 2021).