Asthma has rapidly become one of the most common chronic illnesses of the Western world, and its prevalence continues to rise, with the proportion of patients with more severe diseases also increasing. Faced with this problem, more researchers are focusing on the causes, mechanisms, and pathophysiology of asthma. The major hopes are that more effective drugs will become available and that preventive measures can be instituted. Increasingly, molecular and cell bi- ogy approaches are being used to characterize and understand the mechanisms of the inflammatory process that is typical of the...