AFP and hepatitis A virus infection: 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.