In the supplemental data for the article on page 3837 in the 1 November 2012 issue, the following text was omitted: “and the monoclonal antibody mouse anti-human thrombin.” In the supplemental Materials, the first sentence reads: “Fluorescein isothiocyanate (FITC)-labeled bovine lactadherin, FITC-EGR-chloromethyl ketone (FITC-EGRck) and RVV fX Activator were from Haematologic Technologies Inc. (Essex Junction, VT).” The sentence should have read: “Fluorescein isothiocyanate (FITC)-labeled bovine lactadherin, FITC-EGR-chloromethyl ketone (FITC-EGRck), RVV fX Activator and the monoclonal antibody mouse anti-human thrombin were from Haematologic Technologies Inc. (Essex Junction, VT).” The error has been corrected in the online data supplement.