We found that an intra-individual robust coefficient of variation (RCV) for peripheral blood neutrophil myeloperoxidase expression of less than 30% excluded MDS, with 100% sensitivity and 100% negative predictive value, suggesting that it could obviate the need for bone marrow aspiration in up to 35% of patients referred for suspected disease.10 12. Here, MPO is linked to myelodysplastic syndrome.