CCR1 and colonic neoplasm: In murine colon cancer models, the chemokine receptor CCR1 on myeloid cells instigates them to accumulate in the liver's microenvironment, leading to the secretion of its ligand, CCL9 (akin to CCL15 in humans) in cancer cells, and then potentiates metastasis, indicating that CCR1-positive myeloid cells may participate in the initial phases of hepatic metastases [99].