CXCL1 and breast cancer: Through the study of multiple breast cancer models, we concluded that high abundances of N1 neutrophils and their chemoattractants (CXCL1, CXCL2, and CXCL5) were common and necessary to develop potent antitumor immunity and drive metastatic dormancy in the lungs that had been seeded with breast cancer TCs (Fig. 7j), and their abundance in the lungs was influenced by the metastatic properties of the primary tumor and the host immunity.