According to a systematic review, the sensitivity, specificity, and LR+ of AFP in HCC smaller than 5 cm in diameter ranged from 0.49 to 0.71, 0.49 to 0.86, and 1.28 to 4.03, respectively, with cut-off value of 20 ng/mL and from 0.04 to 0.31, 0.76 to 1.0, and 1.13 to 54.25, respectively, with cut-off value of 200 ng/mL [323]. This evidence concerns the gene AFP and hepatocellular carcinoma.