VWF and acute respiratory distress syndrome: In patients with ARDS, various endothelial injury markers, e.g., von Willebrand factor (VWF; Ware et al., 2004), can be detected in blood and epithelial apoptotic markers, e.g., cytokeratin-18 (Lee et al., 2008; Galani et al., 2010), and can be measured in bronchoalveolar lavage (BAL) fluid.