Below is an instruction from Human. Write a response.
    ### Instruction:
    What is (are) neuroblastoma ?
    ### Response:
    Neuroblastoma is a type of cancer that most often affects children. Neuroblastoma occurs when immature nerve cells called neuroblasts become abnormal and multiply uncontrollably to form a tumor. Most commonly, the tumor originates in the nerve tissue of the adrenal gland located above each kidney.
    