In addition, to address whether the accumulation of immature MDS cells is linked with high expression of CXCL12, we quantified the expression in ex vivo expanded MSCs from n = 6 high-risk patients with MDS, which achieved complete remission (ie, blast clearance <5%) upon treatment with hypomethylating agents, and observed that the MSCs at remission significantly expressed lower levels of CXCL12 (supplemental Figure 9D). The gene discussed is CXCL12; the disease is myelodysplastic syndrome.