AFP and hepatocellular carcinoma: In detail, they proposed the following downstaging criteria for patients beyond the Milan criteria: single HCC 5–6 cm, two HCCs ≤ 5 cm, or less than six HCCs ≤ 4 cm and the sum of diameter ≤ 12 cm, but within the Milan criteria with a stability period of three months, including AFP stably below 400 ng/mL after the downstaging procedures.