The mean change from baseline Hb at the end of treatment (up to 16 weeks) was lowest in patients with advanced NSCLC: 0.6 and 1.3 g/dL in the darbepoetin alfa and epoetin alfa groups, respectively, in comparison with increases of 1.7–1.9 g/dL or 1.3 g/dL in patients with breast cancer or gynecologic cancer. The gene discussed is GSTM1; the disease is breast cancer.