Furthermore, the active segments of the diphtheria toxin (DITOX) and the Pseudomonas aeruginosa exotoxin (PE24) were integrated with T22 and H6 to fabricate self-assembled toxin-based nanoparticles T22-DITOX-H6 and T22-PE24-H6, respectively, and they acted as toroid nanoparticles of 30–90 nm, penetrating the CXCR4+ tumor cells and promote tumor cell killing in vitro. Here, CXCR4 is linked to neoplasm.