Below is an instruction from Human. Write a response.
    ### Instruction:
    What is (are) Non-Small Cell Lung Cancer ?
    ### Response:
    Key Points
                    - Non-small cell lung cancer is a disease in which malignant (cancer) cells form in the tissues of the lung.     - There are several types of non-small cell lung cancer.    - Smoking is the major risk factor for non-small cell lung cancer.
    