Moreover, analysis based on TCGA database showed that the expression levels of 12 significant DEGs (except GIF) were significantly different between GC tissues and adjacent normal gastric tissues (Figure 3A), and statistical correlation could also be found between the expression levels of COL1A2, TIMP1, THY1, and BGN and tumor stage (Figure 3B). The gene discussed is COL1A2; the disease is neoplasm.