Methemoglobin is a serum glycoprotein synthesized by the liver during early fetal life. After birth, the level of fetoprotein in blood is extremely low, less than 25ug/L. When malignant tumors occur in hepatocytes or reproductive system tissues, the synthesis of fetoprotein by the body increases, resulting in a significant increase in the level of fetoprotein in blood. Therefore, the detection of fetoprotein concentration in blood has important clinical value for the diagnosis of hepatocellular carcinoma and malignant tumors of the reproductive system. Carcinoembryonic antigen is a broad-spectrum tumor marker that can be manifested in a variety of tumors with low specificity, and is mainly used in clinical practice for the adjuvant diagnosis of malignant tumors, judgment of prognosis, monitoring of therapeutic efficacy and tumor recurrence. Elevated carcinoembryonic antigen is mainly seen in patients with pancreatic cancer, colon cancer, rectal cancer, breast cancer, gastric cancer and lung cancer. Generally, the concentration of carcinoembryonic antigen decreases when the disease improves and increases when the disease worsens.