In summary, it appears that differential expression of COL4A1, EGFR, BTF3, MPP2, RAB31, CDK4, CD99, ANXA2, TOP2A, and SERBP1 genes may be required for the development of glioblastoma (GBM), the most common type of malignant brain tumor. The gene discussed is CDK4; the disease is glioblastoma.