AFP and hepatocellular carcinoma: GPC-3 is a hepatocellular carcinoma related biomarker with a specificity of up to 97%, which can detect hepatocellular carcinoma at an earlier stage than AFP and one study showed that serum GPC-3 levels in 50% of patients with early hepatocellular carcinoma were > 300 ng/L, despite their serum AFP levels < 100 μg/L (50).