VCAM1 and acute respiratory distress syndrome: Immunohistochemical (IHC) staining of lung tissue showed that the expression levels of VLA-4 and VCAM-1 (the counter-receptor of VLA-4) had increased significantly 24 h after LPS-induced ALI compared with the control (VLA-4, 4.7% vs. 44.1%; VCAM-1, 4.0% vs. 62.9%; both p < 0.05).