We observed that 2/60 (3%) IDHmut astrocytomas were reclassified as A4IDHmut due to CDKN2A/B homozygous deletion and 5/60 (8%) of IDHwt grades 2 and 3 were reclassified as GBMs (grade 4) due to one or more alterations in TERT, EGFR, and chromosomes 7 and 10, under the 2021 WHO criteria. Here, CDKN2A is linked to astrocytoma (excluding glioblastoma).