Pathogenesis and natural history of usual interstitial pneumonia: the whole story or the last chapter of a long novel.

Idiopathic pulmonary fibrosis (IPF)/usual interstitial pneumonia (UIP) is not well-understood. Current explanations of the natural history and pathogenesis of IPF/UIP are controversial, and ongoing research continues to investigate multiple hypotheses. A complete understanding of the natural history of IPF could potentially help to identify different mechanisms that are operative at the early, intermediate, and end stages of the disease. This knowledge could lead to the development of more effective therapeutic interventions that target stage-specific aberrant pathways involved in IPF/UIP pathogenesis.