Below is an instruction from Human. Write a response.
    ### Instruction:
    What is (are) Hypersensitivity Pneumonitis ?
    ### Response:
    Hypersensitivity pneumonitis (noo-mo-NI-tis), or HP, is a disease in which the lungs become inflamed from breathing in foreign substances, such as molds, dusts, and chemicals. These substances also are known as antigens (AN-tih-jens).
                
People are exposed to antigens at home, while at work, and in other settings.
    