Below is an instruction from Human. Write a response.
    ### Instruction:
    What causes Bronchiolitis obliterans organizing pneumonia ?
    ### Response:
    What causes bronchiolitis obliterans organizing pneumonia (BOOP)? BOOP may be caused by a variety of factors, including viral infections, inhalation of toxic gases, drugs, connective tissue disorders, radiation therapy, cocaine, inflammatory bowl disease, and HIV infection.
    