To improve the diagnostic accuracy of early HBV-related HCC tumors, another serum biomarker, namely, protein induced by vitamin K absence or antagonists-II (PIVKA-II), had been practically evaluated in large cohort studies for combinatorial use with AFP, although the detection sensitivity and specificity for tumors <2 cm was only marginally improved [135,136,137]. The gene discussed is AFP; the disease is hepatocellular carcinoma.