Lung stem cells -- for real?

There's good, stem cell-related news for another organ this week -- the lung. Researchers say they have found lung stem cells, which may hold therapeutic value for repairing damaged respiratory tissue, according to a study published this week in the New England Journal of Medicine (NEJM). The team identified the lung stem cells from human lungs in a tissue bank using specific genetic markers, and demonstrated their stem-cell-ness by confirming that they could self-renew and differentiate into several different types of lung tissue. When injected into injured mouse lungs, the cells replaced the damaged tissue.

The finding is likely to generate debate and skepticism within the field, however, The Boston Globe reports, because many scientists did not expect such a dynamic lung stem cell to exist. Indeed, "several cells [of the lung] have been claimed to possess the properties of stem cells, but don't have the biological characteristics,"...