Below is an instruction from Human. Write a response.
    ### Instruction:
    What is (are) celiac disease ?
    ### Response:
    Celiac disease is a condition in which the immune system is abnormally sensitive to gluten, a protein found in wheat, rye, and barley. Celiac disease is an autoimmune disorder; autoimmune disorders occur when the immune system malfunctions and attacks the body's own tissues and organs.
    