In addition to this mobilization, chemokines such as CCL2, CCL3, CCL4, and colony-stimulating factor 1 (CSF-1), which are already expressed by cancer cells at the tumor site, drive TAM differentiation and polarization into either classically activated M1 macrophages or immunosuppressive M2 macrophages within the TME [51]. Here, CSF1 is linked to neoplasm.