GSTM1 and type 2 diabetes mellitus: The TREAT trial randomized anemic patients with type 2 diabetes and CKD to darbepoetin alfa treatment, with a target Hb level of 13 g/dL (Group 1), or the administration of placebo (Group 2), with rescue darbepoetin alfa given to patients in Group 2 only if Hb levels dropped below 9 g/dL (Pfeffer et al., 2009).