As reported in previous, CXCR4/p-Akt signaling correlated unfavorable outcome of acute myeloid leukemia patients via upregulation of vascular endothelial growth factor (VEGF) and IL-6 gene expression [36]; in this study, we found decreased protein levels of VEGF and IL-6 coincided with CXCR4 reduction in the xenograft-transplantation model of breast cancer cells carrying miR-139 (Figure 5G). Here, CXCR4 is linked to breast cancer.