Below is an instruction from Human. Write a response.
    ### Instruction:
    What is (are) Behcet's Disease ?
    ### Response:
    Behcet's disease is a rare, chronic inflammatory disorder. The cause of Behcet's disease is unknown, but current research suggests that both genetic and environmental factors play a role. Behcet's disease generally begins when individuals are in their 20s or 30s, although it can happen at any age.
    