Below is an instruction from Human. Write a response.
    ### Instruction:
    What is (are) Melanoma ?
    ### Response:
    Key Points
                    - Melanoma is a disease in which malignant (cancer) cells form in melanocytes (cells that color the skin).    - There are different types of cancer that start in the skin.    - Melanoma can occur anywhere on the skin.     - Unusual moles, exposure to sunlight, and health history can affect the risk of melanoma.
    