Below is an instruction from Human. Write a response.
    ### Instruction:
    What is (are) Liver (Hepatocellular) Cancer ?
    ### Response:
    Key Points
                    - Liver cancer is a disease in which malignant (cancer) cells form in the tissues of the liver.    - Liver cancer is not common in the United States.    - Being infected with certain types of the hepatitis virus can cause hepatitis and increase the risk of liver cancer.
    