S100A9 and myelodysplastic syndrome: These results suggest that apoptotic signals are upregulated in MDS bone marrow via TNFR‐I‐TNFα, FAS‐FASL and other systems.24, 25, 26, 27 Moreover, CCL3, TGF‐β, S100A9, S100A8 and interleukin (IL)1β have been shown to be overexpressed in bone marrow stromal cells of patients with MDS, further contributing to the induction of apoptosis in hematopoietic cells.28