CD274 and colorectal carcinoma: Programmed cell death-1 ligand 1 (PD-L1) leads to upregulation of M2 macrophages in the TME through activation of signal transducer and activation of transcription 3 (STAT 3)/nuclear factor kappa-B (NF- κ B) signaling pathway, leading to immunosuppression and EMT in CRC (28).