Uncommon version seems to lessen risk of lung disease in smokers People who carry a variant form of a gene that encodes a protein called MMP-12 are in luck. This uncommon form of the gene appears to provide some protection against emphysema and asthma, researchers report online December 16 in the New England Journal of Medicine. In the study, an international team of researchers analyzed data on lung function and genetics from seven studies that included more than 5,000 people and found that 7 to 13 percent of people harbored the beneficial variant of MMP-12. In four of the studies,...