Then, six collagen genes (COL1A1, COL1A2, COL3A1, COL4A1, COL4A2, and COL5A2) were selected for further validation in Oncomine, TCGA (The Cancer Genome Atlas), and CGGA (Chinese Glioma Genome Atlas) database. The gene discussed is COL4A2; the disease is central nervous system cancer.