Figure 5 Localisation of factor VII activating protease (FSAP) in lung tissue. Sections from lung tissue of patients with acute respiratory distress syndrome (ARDS) (A–C) or controls (myocardial infarction; D–F) were stained for FSAP with specific antibodies (brown colour). In ARDS, strong immunoreactivity for FSAP was observed in (A) alveolar macrophages, (B) endothelial cells and (C) bronchial epithelial cells. In controls FSAP protein was detected in alveolar macrophages only (D) and not in other cells such as (E) endothelial or (F) bronchial epithelial cells. One representative patient out of seven with ARDS and five controls is shown. Bar = 5 μm.