Here's an interesting article from a few days ago:

Adult Stem Cells Migrate to Lung, Contribute to Pulmonary Fibrosis

09 Aug 2004

UCLA researchers for the first time identified and then stopped a type of adult stem cell from migrating to the lung and contributing to pulmonary fibrosis in an animal model. Pulmonary fibrosis (i.e, idiopathic pulmonary fibrosis) in humans is a devastating terminal disorder that causes an overabundance of scar tissue to form in the lung.

IMPACT: The new study may offer novel therapies to treat idiopathic pulmonary fibrosis– currently there are no effective treatments and the mortality rate is approximately 70 percent within five years of diagnosis. Over 80,000 individuals in the United States suffer from the disease. [medicalnewstoday.com]