Below is an instruction from Human. Write a response.
    ### Instruction:
    What is (are) Mantle cell lymphoma ?
    ### Response:
    Mantle cell lymphoma (MCL) belongs to a group of diseases known as  non-Hodgkins lymphomas (NHL), which are cancers that affect the the lymphatic system (part of the immune system). MCL accounts for 6% of all non-Hodgkin lymphomas and is mostly found in males during their early 60s.
    