About the cover: Cover is based on an image showing matrix metalloproteinase-9 (MMP-9) immunolocalization. An MMP-9 antibody was used in an immunofl uorescence assay to examine MMP-9 expression in bronchoalveolar lavage cells from A₃R+/+ mice exposed to bleomycin. For more information, see article by Morschl and colleagues beginning on page 697.