AFU is another sensitive and specific new marker for the detection of primary hepatocellular carcinoma. Serum AFU activity is significantly higher in patients with primary hepatocellular carcinoma than in other types of diseases (including benign and malignant tumors). However, it is worth mentioning that there is some overlap between serum AFU activity measurements in some metastatic liver cancer, lung cancer, breast cancer, ovarian or uterine cancer, and even in some non-neoplastic diseases such as cirrhosis, chronic hepatitis and gastrointestinal bleeding, which are also mildly elevated. The use of AFU should be measured simultaneously with AFP to improve the diagnosis of primary hepatocellular carcinoma, which has a better complementary effect.