Using subtractive-EMSA-SELEX and MALDI-TOF MS assay they verified that VASN was highly expressed in alpha-fetoprotein (AFP, a classical serological biomarker for liver cancer) negative sera of 100 cases of HCC patients with extrahepatic metastases compared with 97 cases of healthy controls, and 129 cases of hepatitis patients. Here, AFP is linked to hepatocellular carcinoma.