Below is an instruction from Human. Write a response.
    ### Instruction:
    What is (are) Gastrointestinal Stromal Tumors ?
    ### Response:
    Key Points
                    - Gastrointestinal stromal tumor is a disease in which abnormal cells form in the tissues of the gastrointestinal tract.    - Genetic factors can increase the risk of having a gastrointestinal stromal tumor.     - Signs of gastrointestinal stromal tumors include blood in the stool or vomit.
    