Statistical analysis of these results revealed that SMAD7, HIF-1α expression, serum HIF-1α and CEA level were significantly upregulated in GC patients as compared to control group (P = 0.024, < 0.001, < 0.001, < 0.001) and had significant positive correlations between each other except SMAD7 with serum HIF-1α (rs = 0.177, P = 0.078), and CEA level (rs = 0.169, P = 0.093). The gene discussed is HIF1A; the disease is gastric cancer.