Clinical scenarios in which RBC transfusion was considered appropriate were (based on the official consensus document from 2013): Hb < 70 g/L (acute anemia irrespective of sign/symptoms), Hb < 80 g/L (chronic anemia with symptoms of anemia or risk factors), Hb < 90 g/L (acute anemia with hemodynamic instability, CAD, heart failure, cerebrovascular disease, and myocardial infarction), and Hb ≥ 90 g/L (acute anemia with hemorrhage or symptoms of anemia) [24]. This evidence concerns the gene GSTM1 and anemia.