The normal value of AFP is less than 9ng/mL, which is an embryonic protein that can be significantly elevated in liver cancer. If the value of methemoglobin is greater than 400ng/mL, you should be highly alert to the occurrence of liver cancer and must undergo liver imaging examination, which is commonly used to further determine and screen liver cancer. Causes of liver cancer include chronic hepatitis B and chronic hepatitis C. People with family history of liver cancer or long-term excessive alcohol consumption are prone to get liver cancer. Alpha-fetoprotein is very useful for screening liver cancer. Men with risk factors should have their alpha-fetoprotein checked regularly. The normal value of alpha-fetoprotein is less than 9ng/mL, and dynamic observation should be performed when it is high.