COG2 and glioblastoma: Analyze the expression of 9 model genes in the training set; then, the results showed that these 6 genes, STC1, SRD5A3, MDH2, IL13RA1, TGFBI, and B3GAT3, were all highly expressed, while HDAC4, COG2, and G6PC2 genes were all downregulated in patients with GBM (Figure 4).