Below is an instruction from Human. Write a response.
    ### Instruction:
    What is (are) Multiple Myeloma ?
    ### Response:
    Multiple myeloma is a cancer that begins in plasma cells, a type of white blood cell. These cells are part of your immune system, which helps protect the body from germs and other harmful substances. In time, myeloma cells collect in the bone marrow and in the solid parts of bones.
    