In the editorial entitled “CFC transition: the Emperor's new clothes—each class of drug deserves a delivery system that meets its own requirements” published on pages 811–4 of the October 2000 issue of Thorax an error appeared in the first sentence of the second paragraph on page 811. This should have read “It seems probable that, during the later part of 2001, the FDA will grant a licence to deliver insulin as an aerosol.”