Through review of the literature, we identified the 9 most common thrombophilias as factor VIII excess, activated protein C resistance, hyperhomocysteinemia, anticardiolipin antibody, lupus anticoagulant, prothrombin G20210A mutation, protein S deficiency, antithrombin deficiency, and protein C deficiency. The gene discussed is PROS1; the disease is hyperinsulinemic hypoglycemia, familial, 4.