CXCR4 and myelodysplastic syndrome: The unfavorable prognostic significance provides a rationale for the targeting of CXCL12+ stromal cells and/or the chemokine (C-X-C motif) receptor 4 (CXCR4)/CXCL12 axis, which has shown promising results in mice [184], and is currently being explored in clinical trials of MDS and AML [185,186].