An alpha-fetoprotein of 6.67 U/ml is approximately equal to 6ug/L, which is within the normal range. The reference value for alpha-fetoprotein is 25ug/L or less. Alpha-fetoprotein is a serum glycoprotein synthesized by the liver and yolk sac in the early fetal period, and its synthesis is quickly inhibited after birth. When malignant lesions occur in liver cells, the cells that have lost the ability to synthesize alpha-fetoprotein start synthesizing it again, so the blood alpha-fetoprotein concentration test is of great value in diagnosing hepatocellular carcinoma. However, other diseases such as hepatitis, cirrhosis, pregnancy, etc. may also show elevation of this index, only the degree of elevation varies. A fetoprotein higher than 300ug/L is present in about half of patients with primary hepatocellular carcinoma, but a small percentage of patients do not have elevated levels either. In viral hepatitis and cirrhosis, alpha-fetoprotein is generally elevated to varying degrees, usually less than 300ug/L. In pregnant women, alpha-fetoprotein is also elevated, but mostly less than 400ug/L, and returns to normal 3 weeks after delivery. If abnormal elevation of alpha-fetoprotein occurs, it is recommended to consult a doctor in time and take care of it with the help of a doctor.