Genome-wide association studies have identified CDKN2A as a susceptibility locus for GBM, further highlighting its role in tumorigenesis.167,168 CDKN2A deletion is strongly linked to worse OS in astrocytoma patients, suggesting its utility as a prognostic biomarker.169 Lower CDKN2A expression is correlated with higher tumor grade and aggressive disease, reinforcing its relevance in glioma classification. This evidence concerns the gene CDKN2A and astrocytoma (excluding glioblastoma).