Below is an instruction from Human. Write a response.
    ### Instruction:
    What is (are) idiopathic pulmonary fibrosis ?
    ### Response:
    Idiopathic pulmonary fibrosis is a chronic, progressive lung disease. This condition causes scar tissue (fibrosis) to build up in the lungs, which makes the lungs unable to transport oxygen into the bloodstream effectively. The disease usually affects people between the ages of 50 and 70.
    