S100A9 and myelodysplastic syndrome: Another study that focused on circulating S100A8 and S100A9 homodimers and S100A8/A9 heterodimers in plasma from 58 severe aplastic anemia (SAA) and 30 MDS patients, showed that circulating S100A8 was increased in MDS compared to those of SAA and/or healthy controls, and that it may be useful to distinguish these diseases in the differential diagnosis of bone marrow failure syndromes.