GSTM1 and anemia (phenotype): Although full correction of anemia from low Hb concentrations have been shown to increase morbidity and mortality in CKD patients (Singh et al. 2006; Drüeke et al. 2006; Pfeffer et al. 2009), partial correction has been shown to improve cardiac function (Hayashi et al. 2000), cognitive function (Pickett et al. 1999) and quality of life in CKD patients (Revicki et al. 1995; Drüeke et al. 2006).