CXCR4 and breast cancer: On the basis of the crucial role of SDF1/CXCR4 in breast cancer metastasis to femora, tibiae, and mandibles, we systemically injected via an intracardiac route MDA-MB-231-luc+ cells to test the ability of TQ to modulate CXCR4 expression and thereby inhibit metastasis to the bones and other organs.