Below is an instruction from Human. Write a response.
    ### Instruction:
    What is (are) Neuroblastoma ?
    ### Response:
    Key Points
                    - Neuroblastoma is a disease in which malignant (cancer) cells form in nerve tissue.    - Most cases of neuroblastoma are diagnosed before 1 year of age.     - The risk factors for neuroblastoma are not known.
                

    