CXCR4 and neoplasm: In order to test whether Cxcr4 signaling inhibition in the microenvironment could affect the metastatic cascade in other tumor types, we engrafted another triple negative breast cancer cell line MDA-MB-157 (Fig. 3A,B), as well as prostate cancer cells PC3-M-Pro4-Luc2 (Fig. 3C,D) and the Ewing sarcoma cell line WE68 (Fig. 3E,F).