GSTM1 and Renal insufficiency: Only in recent years have a number of representative registered clinical trials (the Cardiovascular Risk Reduction by Early Anemia Treatment with Epoetin Beta (CREATE), the Correction of Hemoglobin and Outcomes in Renal Insufficiency (CHOIR) and the Trial to Reduce Cardiovascular Events with Aranesp Therapy (TREAT)) reported higher target Hb concentrations of 13–15, 13.5 and 13.5 g/dL, respectively [12–14].