Left Panel: Lung tissue from a mouse 28 days post-treatment with bleomycin. The tissue section, which was stained with Gomori's Trichrome stain shows increased collagen (blue) in the lung parenchyma. Right Panel: In situ binding assay showing the binding of rhCXCL8 to alveolar macrophages, alveolar septa, and the cell surface of airway epithelial cells. In this confocal image, rhCXCL8 is stained red, nuclei are stained with ToPro-3 (Blue), and tissue autofluorescence (green) provides structural details. See Hayashida et al., on page 925, in this issue.