Gene expression profiling studies also demonstrate that IFN-γ and chemokine signaling, as well as apoptosis-associated pathways, are overexpressed in CD34+ stem cells of patients with early MDS [31], and that activating mutations in TLR2 which upregulate IL-8 expression are present in stem cells of MDS patients [32]. This evidence concerns the gene CD34 and myelodysplastic syndrome.