Tumor indicators include various items, each with different reference values, and tumor indicators are not diagnostic criteria, but can be used as a basis for clinical treatment or as a tumor screening indicator, e.g., a normal value of methemoglobin is less than 25ug/L, and a value consistently greater than 400ug/L is meaningful for the diagnosis of liver cancer. In the normal population, such as women during pregnancy, the value of alpha fetoprotein may be increased, but it is normal. In clinical diagnosis of tumor, detailed physical examination combined with multiple test results are required.