Leukocyte navigation mechanisms as targets in airway diseases.

Respiratory diseases, including asthma and chronic obstructive pulmonary disease, are among the most significant diseases in terms of their disabling effects and healthcare burden. A characteristic feature of almost all respiratory diseases is the accumulation and activation of inflammatory leukocytes in the lung or airway. Recent advances in the understanding of the molecules and intracellular signalling events controlling these processes are now translating to new therapeutic entities. In this article, the process of leukocyte accumulation is summarized, together with the preclinical and clinical evidence supporting the utility of the individual components of this process as targets for disease therapy.