GPC3 and hepatocellular carcinoma: Among the twenty-two studies, eighteen of them have demonstrated that serum GPC3 level is higher in HCC patients than that in control subjects, which include healthy individuals and patients with hepatitis or liver cirrhosis [10–27] (Table 1), whereas four studies have claimed that GPC3 is not a diagnostic marker for HCC because serum GPC3 level is lower in HCC patients than that in patients with liver cirrhosis [28–31].