rFVIIa binds to tissue factor exposed on injured tissue to activate factor IX, factor X, and platelets.9 In addition, high concentrations of factor VIIa can directly activate platelets and local thrombin formation.10 rFVIIa may be effective in treating persistent skin and muscle bleeding, and intraoperative bleeding.11 However, successful thrombin generation requires activation of FX downstream of FVII, and rFVIIa may be ineffective in cases of severe FX deficiency. The gene discussed is F10; the disease is hyperinsulinemic hypoglycemia, familial, 4.