Tobacco Smoking and Somatic Mutations in Human Bronchial Epithelium

This interesting study compared bronchial epithelial mutation burden, the primary source of new lung cancers, among nonsmokers, former smokers, and current smokers.  Smoking typically adds 1,000 to 10,000 mutations per cell.  Smoking cessation in this study was associated with replenishment of the abnormal epithelium with cells that are typical of nonsmokers and have a normal mutagenic potential.