Below is an instruction from Human. Write a response.
    ### Instruction:
    What is (are) Paraneoplastic Syndromes ?
    ### Response:
    Paraneoplastic syndromes are a group of rare disorders that are triggered by an abnormal immune system response to a cancerous tumor known as a "neoplasm." Paraneoplastic syndromes are thought to happen when cancer-fighting antibodies or white blood cells (known as T cells) mistakenly attack normal cells in the nervous system.
    