Double staining of vimentin and ROCK1. Immunostaining for ROCK1 (A and D) and vimentin (B and E) in COPD tissue sections. Cell nuclei are visualized by DAPI staining, shown in blue. (C) and (F) show merged images. (A), (B) and (C) show a small airway and (D), (E) and (F) alveolar parenchyma. Inserts show cells positive for both ROCK1 and vimentin with fibroblast-like morphology as indicated by closed arrowheads. Open arrowheads show rounded double-positive cells that are likely to be alveolar macrophages. Scale bars represent 50 μm of the larger image and 10 μm on inserts.