GSTM1 and chronic kidney disease: The Trial to Reduce Cardiovascular Events with Aranesp Therapy (TREAT) studied diabetic patients with CKD not on dialysis, and found a clear doubling of stroke risk in the higher Hb target arm (target Hb 13 vs. 9 g/dl, HR 1.92, 95% CI 1.38–2.68) (19), a hazard that was not modified by any baseline characteristic.