Thrombin induces CD54 expression on HUVECs (FACS analysis). HUVECs were cultured for 6 hours (left side) and 24 hours (right side) in culture medium (upper panels), in the presence of 8 U/mL of thrombin (intermediate panels), or in the presence of thrombin with hirudin (lower panels). After cell trypsinization, CD54 expression was studied by FACS analysis (1 representative experiment among 5).