idiopathic interstitial pneumonia (MONDO_0002429) is a class of diffuse lung diseases that typically affect the pulmonary interstitium, although some also have a component affecting the airways (for instance, Cryptogenic organizing pneumonitis). Also known as: IIP, IIp, diffuse idiopathic pulmonary fibrosis, idiopathic fibrosing alveolitis, idiopathic interstitial pneumonitis, noninfectious pneumonia.