Below is an instruction from Human. Write a response.
    ### Instruction:
    What is (are) Childhood Hodgkin Lymphoma ?
    ### Response:
    Key Points
                    - Childhood Hodgkin lymphoma is a disease in which malignant (cancer) cells form in the lymph system.    - There are two types of childhood Hodgkin lymphoma.     - Epstein-Barr virus infection increases the risk of childhood Hodgkin lymphoma.
    