Further studies reveal that CRC-derived miR-21-5p and miR-200a synergistically induces macrophage M2 like polarization and PD-L1 expression by regulating the PTEN/AKT and SCOS1/STAT1 pathways, resulting in decreased CD8<sup>+</sup> T cell activity and increased tumor growth. The gene discussed is CD8A; the disease is colorectal carcinoma.