Below is an instruction from Human. Write a response.
    ### Instruction:
    What is (are) Glioblastoma ?
    ### Response:
    Glioblastoma is a malignant (cancerous) brain tumor that develops from a specific type of brain cell called an astrocyte. These cells help support and nourish neurons (nerve cells of the brain) and form scar tissue that helps repair brain damage in response to injury.
    