Although in this study we did not address the progression of carotid atherosclerosis in relation to GSTM1 genotype, it may be speculated that the deleterious effect of GSTM1-null genotype might be even more pronounced in ESRD patients than in smokers, because of their higher exposure to dialysis-related oxidant stress. This evidence concerns the gene GSTM1 and carotid atherosclerosis.