Smoking plays a role in lung cancer development and now scientists have shown that smoking also affects the way genes are expressed, leading to alterations in cell division and regulation of immune response. Notably, some of the changes in gene expression persisted in people who had quit smoking many years earlier. These findings by researchers at the National Cancer Institute (NCI), part of the National Institutes of Health, appeared in the Feb. 20, 2008, issue of PLoS ONE.
