About the cover: Cover is based on an image of immunolocalization of glycosaminoglycans in human airways. Human trachea sections were double-labeled with mouse anti–keratan sulfate and biotinylated hyaluronan (HA) binding protein for HA. Confocal microscopy images show specific fluorescence in airway epithelium. For more information, see article by Monzon and colleagues, beginning on page 135.