1. From the Medical Molecular Biology Unit (K.M.L., A.C., T.S., M.H., A.S., D.S.L.), Institute of Child Health, University College London, London, England; Cardiovascular Pathophysiology Research Centre (E.P., L.C., R.F.), S. Maugeri Foundation IRCCS, University of Ferrara, Italy; Centre for Clinical Pharmacology (A.T.), Department of Medicine, University College London, England; and National Heart and Lung Institute (R.A.K.), Royal Brompton Hospital, London, England.