Final answer:
Hepatitis B Virus (HBV) is a highly infectious disease that affects the liver. It can cause inflammation and damage to the liver and increase the risk of liver cancer.
Step-by-step explanation:
The highly infectious disease that affects the liver is Hepatitis B Virus (HBV). Hepatitis B is inflammation of the liver caused by infection with the hepatitis B virus. It can lead to liver damage and increase the risk of liver cancer. Chronic infection of the liver by this virus can result in the development of liver cancer years after the initial infection.