Smoking leads to diseases such as chronic obstructive pulmonary disease, or COPD. And researchers at the University of Alabama at say they can see a key part of how it happens. The researchers say smoke blocks an enzyme that shuts off white blood cells after the cells successfully attack the cause of an inflammation, so inflammation continues – in other words, becomes chronic. However, researcher Ed Blalock says giving up smoking could fix that: "If you stop smoking, you’ll in a sense allow your body to essentially heal itself, if you will – or at least overcome the insult." The study in Science Express was supported by the National Institutes of Health.