In the CRLM model, not only did Varney et al. [59] find that the microvessel density in liver metastases from mice treated with a CXCR1/2 antagonist is lower but they found that the apoptosis rate of the tumor cells was also higher in the CXCR1/2 antagonist-treated groups than in the control groups, which indicated that the CXCL8-CXCR1/2 signal axis promoted the growth and survival of tumor cells in the liver metastases. This evidence concerns the gene CXCR1 and neoplasm.