Below is an instruction from Human. Write a response.
    ### Instruction:
    What is (are) Immune System and Disorders ?
    ### Response:
    Your immune system is a complex network of cells, tissues, and organs that work together to defend against germs. It helps your body to recognize these "foreign" invaders. Then its job is to keep them out, or if it can't, to find and destroy them.    If your immune system cannot do its job, the results can be serious.
    