CD274 and colorectal carcinoma: Mechanistic investigations reveal that CRC cells can secrete small extracellular vesicles (sEVs) taken up by macrophages that induce M2 like polarization and PD-L1 expression, resulting in increased PD-L1<sup>+</sup>CD206<sup>+</sup> macrophage abundance and decreased T cell activity in CRC TME.