This revised 2021 WHO CNS5 tumor classification system marked a paradigm shift by fully integrating molecular features into glioma classification and grading, combining traditional histopathological evaluation with key molecular markers (e.g., IDH mutation status, 1p/19q codeletion, CDKN2A/B deletions, and histone mutations) to more accurately reflect the biological prognosis, and predictive therapeutic implications of these tumors (1) (Table 1). This evidence concerns the gene CDKN2A and central nervous system cancer.