It was found that EMT-CRC cell-derived extracellular vesicles highly expressing microRNA-106b-5p promoted M2 polarization of macrophages by directly inhibiting activation of the phosphatidylinositol 3-kinase (PI3K) γ/AKT/mTOR signaling pathway at the post-transcriptional level of programmed cell death 4 (PDCD4). This evidence concerns the gene PDCD4 and colorectal carcinoma.