Below is an instruction from Human. Write a response.
    ### Instruction:
    What is (are) Melanoma ?
    ### Response:
    Melanoma is the most serious type of skin cancer. Often the first sign of melanoma is a change in the size, shape, color, or feel of a mole. Most melanomas have a black or black-blue area. Melanoma may also appear as a new mole. It may be black, abnormal, or "ugly looking.
    