CCL2 and cancer: Furthermore, increased CCL2 expression in the TME is accompanied by increased CCR2 expression on TAMs and by the polarization of macrophages toward the M2 phenotype, whereas CCL2 overexpression and high TCF4 expression correlate with cancer metastasis to lymph nodes and have been linked to poor prognosis because the TCF4/CCL2/CCR2 regulation axis regulated TAM polarization (146).