Based on the molecular makers, all cases were diagnosed as “astrocytoma, IDH-mutant.” Twenty-six cases of astrocytoma showed MTAP staining and were classified as CDKN2A-intact, while the other cases with loss of MTAP staining were classified as CDKN2A-HD. The gene discussed is CDKN2A; the disease is astrocytoma (excluding glioblastoma).