Hermann et al. showed that two groups of mice injected CD133+ CXCR4+ and CD133+ CXCR4− cells appeared similar tumor development in the early stage, but followed with liver metastases or no any trace of metastases 2 weeks later in CXCR4+ group and CXCR4−group respectively [14]. The gene discussed is CXCR4; the disease is neoplasm.