Although EDTA allows for a prolonged conservation of the samples over time,19 it may induce a change of expression patterns of antigens such as CD11b (Figure 1).21 Due to this, heparin has been recommended by the ELN myelodysplastic syndromes (MDS) workgroup.22,23 However, the other anticoagulants are acceptable as long as the laboratory validates its assay for stability.24 This evidence concerns the gene ITGAM and myelodysplastic syndrome.