However, as a surveillance test AFP has a suboptimal performance for two reasons: firstly, because the fluctuating levels of this marker in cirrhotic patients can be related to different situations, such as flare-ups of HBV or HCV-related infection, exacerbation of an underlying liver disease or development of HCC; secondly, because only 10–20% of tumors in the early growth phase cause abnormal levels of AFP in the serum [22]. The gene discussed is AFP; the disease is hepatocellular carcinoma.