CD274 and neoplasm: Immunoregulation using CpG ODNs at the tumor site could promote the maturation and antigen presentation of dendritic cells (DCs) and activate the rapid proliferation and infiltration of cytotoxic T lymphocytes (CTLs) in TME, thereby restoring resistance to the PD-L1 blockade and inhibiting the growth, metastasis and recurrence of CT26 or MC38 cell-driven CRC [27,28].