Below is an instruction from Human. Write a response.
    ### Instruction:
    Who is at risk for Merkel Cell Carcinoma? ?
    ### Response:
    un exposure and having a weak immune system can affect the risk of Merkel cell carcinoma. Anything that increases your risk of getting a disease is called a risk factor. Having a risk factor does not mean that you will get cancer; not having risk factors doesn't mean that you will not get cancer.
    