Cystic fibrosis (CF) is an autosomal recessive disorder affecting approximately 25
,000 persons in the United States. While CF can affect many organ systems, respiratory failure eventually accounts for the vast majority of mortality seen in the disease. Accordingly, despite treatment, many patients will eventually become candidates for lung transplantation. Given the long wait times for transplantable organs, accurate predictors of prognosis are urgently needed to optimize CF patient management.