PROC and Sepsis: The three original studies were large, multicenter RCTs [24-26] of antithrombin III (randomized to the ‘antithrombin III group’ , ‘placebo group’), tissue factor pathway inhibitor (TFPI) (randomized to the ‘drotrecogin alfa (activated) group’ , ‘placebo group’), and recombinant human activated protein C (randomized to the ‘tifacogin group’ , ‘placebo group’) for the treatment of severe sepsis.