CCL2 and colorectal carcinoma: found that TAM infiltration was enhanced in CRC with liver metastasis compared with primary tumors, which was correlated with a worse prognosis.[35] CCL2 contributes to CRC progression by promoting monocyte chemoattraction and TAMs infiltration.[36] In addition, metastasis‐associated macrophages can also be recruited by tumor cell‐derived CCL2 and the CCL2‐CCR2 pathway.