CCL2 and breast cancer: For example, You et al. have reported that in EGFR-positive and HER2-positive basal-like breast cancer, HER2 overexpression leads to significant increases in the secretion of several cytokines, especially Chemokine (C-C motif) ligand 2 (CCL2), which further lead to increased TAM recruitment and production of pro-inflammatory cytokines from M2-polarized TAMs, activating tumorigenesis [34].