CCR5 and breast neoplasm: Another mode of lactate-associated paracrine signaling between TAMs and breast tumor cells was reported by Lin et al., who showed that tumor cell-derived lactate induced the Notch pathway in TAMs to generate CC chemokine ligand 5 (CCL5) which then binds to its receptor CCR5 on breast tumor cells to promote aerobic glycolysis, migration, and epithelial-to-mesenchymal transition (EMT) (123).