Chang Mei-Hwei is the first person in the world to prove that the hepatitis B vaccine can prevent liver cancer in children. She found that the RNA-binding gene on the Y chromosome is the exclusive oncogene of liver cancer. Various studies of her have filled in the missing parts of international papers that lack long-term natural history of childhood hepatitis B virus infection, especially the relationship between the virus and the hosts. Chang Mei-Hwei has made a deep impact on childhood hepatitis and liver cancer research, and extended the concept of this anti-cancer vaccine to other cancers (such as cervical cancer, gastric cancer, and more), hoping that other infectious cancers can be prevented.