Ultrasound with or without alpha-fetoprotein (AFP) has been the cornerstone of HCC screening for over 2 decades, with the American Association for the Study of Liver Disease (AASLD) recommending the combination, ultrasound plus AFP, and the European Association for the Study of the Liver (EASL) recommending ultrasound alone. The gene discussed is AFP; the disease is hepatocellular carcinoma.