Below is an instruction from Human. Write a response.
    ### Instruction:
    What is (are) Mesothelioma ?
    ### Response:
    The tissue that lines your lungs, stomach, heart, and other organs is called mesothelium. Mesothelioma is a tumor of that tissue. It usually starts in the lungs, but can also start in the abdomen or other organs. It can be benign (not cancer) or malignant (cancer.
    