Through exploiting animal tumor models, it has been shown that CCR1 expression increases in colorectal tumor cells during metastasization [40] and that CCR1 sustains liver metastasis by promoting local recruitment of bone marrow (BM)-derived cells that secrete the MMP9 and MMP2 metalloproteinases required for tissue invasion [41]. This evidence concerns the gene CCR1 and colorectal neoplasm.