GSTM1 and intracranial hemorrhage: In the ACTION registry (21), the definition of major bleeding included an absolute Hb decrease of 4 g/dl, intracranial hemorrhage, documented or suspected retroperitoneal bleed, any red cell blood transfusion with baseline Hb of 9 g/dl, or any red cell transfusion with Hb 9 g/dl and a suspected bleeding event.