GSTM1 and breast cancer: We found that Hb level is significantly lower (p<0.002) in node positive BC patients (n=62, mean age: 34.5 years old, mean Hb ± SD: 119.6 ± 14.5 g/l, 95% CI: 116, 123.2) than node negative BC patients (n=74, mean age: 35.5 years old, mean Hb ± SD: 126.7 ± 13.6 g/l, 95% CI: 123.6, 129.8) (Figure 6).