Darbepoetin alfa, a long-acting ESA, is authorized to be administered subcutaneously to patients with symptomatic chemotherapy-induced anemia (hemoglobin [Hb] concentration ≤10 g/dL) at a recommended initial dose of 500 μg (6.75 μg/kg) given once every three weeks. Here, GSTM1 is linked to anemia (phenotype).