We also identified CXCL1 as the most secreted cytokine from TAMs, and CXCL1 reduction using neutralizing antibody or shRNA in TAMs blocked breast cancer cell metastasis in vitro and in vivo, suggesting a role for TAM-secreted CXCL1 in mediating metastasis and its potential as a therapeutic target. Here, CXCL1 is linked to breast carcinoma.