It is estimated that over 5 million people in the UK suffer from lung disease of some kind. These diseases lead to symptoms of breathlessness, reduced mobility and severe disability. They affect 2 ­ 3 children in every classroom and result in over 50 million working days each year being lost to the economy. Many forms of lung disease occur because our natural defence mechanisms are out of control and instead of protecting the lung they actually cause damage. These researchers believe that a chemical called TNF, in a form attached to lung cells, plays a key role in controlling this response. An understanding of the mechanism involved in this process could lead to specific therapeutic targets. Such treatment could allow our natural defence system to revert to its usual protective role and potentially avoid the side effects associated with currently available medication.