CCR5 and colorectal cancer: This polarization process is critical, as it enables the M2 macrophages to secrete C-C motif chemokine ligand 8 (CCL8), a chemokine that, when activated through the CCL8/C-C chemokine receptor type 5 (CCR5)/mTORC1 signaling axis, can significantly promote the proliferation and metastasis of colorectal cancer cells.