CCL2 and colorectal carcinoma: In ESCA, the CCL2-CCR2 axis drives TAM infiltration and M2 polarization, suppressing CD8+ T cells and promoting immune evasion—a pattern mirrored in melanoma, non-small cell lung cancer (NSCLC), and colorectal cancer (CRC), where CCL2 blockade synergizes with immune checkpoint inhibitors (ICIs).