To date, chromosomal gains (+7) and losses (−10), allelic losses (10q, 9p), oncogene amplifications (MDM2, CDK4, EGF), and homozygous deletions and mutations of tumor suppressor genes (CDKN2A, TP53, PTEN, RB1, DMBT1) have been the most frequently found alterations in astrocytoma. The gene discussed is CDKN2A; the disease is astrocytoma (excluding glioblastoma).