CTLA4 and breast cancer: Since anti-CD40 mAbs can induce programmed death ligand 1 (PD-L1) upregulation in TAM and tumor-infiltrating monocyte plasma membrane, the blockade of PD-L1 axis combined with anti-CD40 and anti-CTLA-4 (anti-cytotoxic T-Lymphocyte-associated protein 4) mAbs showed extensive survival in colon and breast cancer models (77).