AFP and hepatocellular carcinoma: The previously established and described DEN-derived, murine hepatoma cell lines were ex vivo isolated from solid tumours, referred as HCC cells (HCC, high proliferation rate and Afp levels), or surrounding liver tissues, referred as precancerous liver cells (preCL, low proliferation rate and Afp levels) of 40-week-old, DEN-treated animals and compared to non-transformed primary isolated hepatocytes ([10] and Figure 4g).