Among the 14 candidate genes, COL1A1 (HR = 1.41, p = 0.042), COL4A1 (HR = 1.45, p = 0.029), COL5A2 (HR = 1.54, p = 0.011), P4HA3 (HR = 1.57, p = 0.011), and SPARC (HR = 1.47, p = 0.022) were associated with the OS of STAD (Figure 6). The gene discussed is COL4A1; the disease is gastric adenocarcinoma.