In the breast cancer lung metastasis model of mice, Wculek and Malanchi [42] found that before breast cancer cells infiltrated the premetastatic lung tissue, CD11b+Ly6G+ neutrophils, the mainly excretive cells of CXCL8, accumulated in the lung first and then facilitated the metastatic cancer cell transfer to the lung. The gene discussed is CXCL8; the disease is breast cancer.