On the other hand, Zinc oxide nanoparticles reduced tumor growth but induced overexpression of cytochrome P450; the effectiveness of zinc oxide nanoparticles via doping with lanthanides, such as samarium, showed more antitumor activity than other lanthanides by downregulating CXCR4 and regulating PI3K/Akt/signaling pathways in Ehrlich solid tumor with minimal toxicity [172]. Here, CXCR4 is linked to neoplasm.