As regard the relationship between target Hb values and the frequency of thromboembolism and vascular accidents in end-stage renal disease (ESRD) patients receiving rHuEPO (Singh et al., 2006), it should be remarked that in some of the trials reporting an higher risk of thromboembolism and related mortality, Hb target levels were above standard, ranging from 13 to 15 g/dl (Henke et al., 2003; Leyland–Jones et al., 2005; Juneja et al., 2008). The gene discussed is GSTM1; the disease is stage 5 chronic kidney disease.