To date, however, the concurrent presence of four such genetic variants—Factor V Leiden (R506Q), MTHFR C677T, PAI-1 4G/5G, and ACE I/D (DD)—has not been reported in a patient with simultaneous arterial and venous thrombosis complicated by massive pulmonary embolism. The gene discussed is SERPINE1; the disease is Venous thrombosis.