PTEN and colorectal carcinoma: Moreover, M2 macrophages -derived exosomes could induce CRC stem cell activity because of containing WNT.115 CRC cell-derived exosomal miR-934 induced M2 macrophage polarization via downregulating PTEN expression and activating the PI3K/AKT signaling pathway.107 Polarized M2 macrophages secreted CXCL13, then activated a CXCL13/CXCR5/NFκB/p65/miR-934 positive feedback loop to induce PMN formation in CRC cells.