The proportion and numbers of CXCR2+ MDSCs markedly increased in peripheral blood, bone marrow, spleen, primary tumor tissues, especially in tumor metastatic lung or lymph nodes, and delineated that CXCR2+ MDSCs not only accelerated tumor growth, but also promoted tumor metastasis to lung or lymph nodes. The gene discussed is CXCR2; the disease is neoplasm.