Recently, the use of bivalirudin as a specific and reversible direct thrombin inhibitor is gradually increasing in order to overcome the limitations encountered with heparin during coronary interventional procedures.37 Bivalirudin carries no risk of heparin-induced thrombocytopenia, does not require a binding cofactor such as antithrombin III, and does not activate platelets.38 Pharmacologically, these characteristics make bivalirudin an ideal alternative to heparin, especially in patients with antithrombin III deficiency or relatively low platelet levels. The gene discussed is SERPINC1; the disease is hyperinsulinemic hypoglycemia, familial, 4.