Very recent works using protein NPs incorporating the T22 peptide [12] to deliver diphtheria toxin, inhibiting invasion and metastasis of CXCR4+ carcinoma mouse cells [13], or CXCR4-targeted modified PAMAM dendrimers aimed at glioblastoma cells [14] demonstrated the importance of chemokine receptors in selective NP delivery. Here, CXCR4 is linked to carcinoma.