Below is an instruction from Human. Write a response.
    ### Instruction:
    What is (are) Muir-Torre syndrome ?
    ### Response:
    Muir-Torre syndrome (MTS) is a form of Lynch syndrome and is characterized by sebaceous (oil gland) skin tumors in association with internal cancers. The most common internal site involved is the gastrointestinal tract (with almost half of affected people having colorectal cancer), followed by the genitourinary tract.
    