SERPINC1 and Sepsis: Here, antithrombin III (ATIII), which inhibits activated proteases including thrombin, seems to play a central role since ATIII levels inversely correlate with the outcome in the setting of sepsis, and ATIII has been shown to block the thrombin pathway of complement activation in a murine model of acute lung injury (Figure 1) [28, 78, 79].