CXCR5 and colorectal carcinoma: Taken as a whole, polarized M2 macrophages trigger pre-metastatic niche arrangement and foster CRLM by excreting CXCL13 and actuating a positive-feedback loop of CXCL13/CXCR5/NF-κB/p65/miR-934 in CRC cells (Figure 4C).