CXCR4 and breast cancer: The interaction between C–X–C motif chemokine ligand 12 (CXCL12) and C–X–C chemokine receptor 4 (CXCR4) plays an important role in promoting tumor growth and migration.[40] NCL can effectively bind to the 212 C‐terminus of CXCR4, which activates CXCR4 signaling in tumor cell growth and synergistically improves tumor invasion and metastasis.[41, 42] The suppressive effects of TB‐5 on BC cells occur via suppression of MMP‐2 expression.