CXCR4 and breast cancer: Chittasupho et al. demonstrated that generation-4 PAMAM dendrimer conjugated with the CXCR4 antagonist, LFC131 (Tyr-Arg-Arg-Nal-Gly) and loaded with doxorubicin, selectively targeted BT-549-Luc breast cancer cells, leading to enhanced cytotoxicity and inhibition of chemotaxis, compared to control dendrimer [25].