S100A9 and myelodysplastic syndrome: Firstly, we measured the S100A9 expression levels in MDS-BM-MNCs with qPCR and found that S100A9 were highly-expressed in lower-risk MDS-BM-MNCs, but showed no difference between higher-risk MDS-BM-MNCs and normal controls; similar results were obtained with ELISA (Figure 1A).