CXCL12 and neoplasm: Lastly, in a third developing approach in addressing CXCR4/CXCL12-mediated drug resistance in TNBC, pharmaceutical engineers are developing a nanoparticle-based delivery system to selectively direct the CXCR4 inhibitors and chemotherapeutics to the tumour tissue to limit systemic toxicity (Table 3) [14].