1 Department of Hepatobiliary Oncology, Cancer Center, Sun Yat-sen University, Guangzhou 510060, China. Chminsh@mail.sysu.edu.cn.
2 Department of Ultrasound, Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Peking University Cancer Hospital & Institute, Beijing 100142, China. minhuachen@bjcancer.org.