Patient prognosis following LT is associated with the risk of HCC recurrence; thus, several selection criteria have been established to help select patients most likely to benefit from an LT, including the Milan criteria (the diameter of a single tumor was less than 5 cm, and the maximum diameter of multiple tumors was less than 3 cm) and the Hangzhou criteria (tumor diameter < 8 cm or tumor diameter > 8 cm, and preoperative AFP < 400 ng/ml and tumor histological grade were high and medium differentiation). The gene discussed is AFP; the disease is hepatocellular carcinoma.