CXCL2 and breast cancer: Although these two types of dormant niches in breast cancer were different, they had common features, including (1) potent Th1 and Th17 pro-inflammatory response, (2) abundant immune cells with pro-inflammatory and antitumor phenotypes such as N1 neutrophils, and (3) abundant chemoattractants for N1 neutrophils (CXCL1, CXCL2, and CXCL5).