CD274 and neoplasm: Thus, by blocking the interaction of PD-L1, on tumor cells, with PD-1 and B7.1 receptors, on tumor-infiltrating T-cells and antigen-presenting cells, the anti-PD-L1 monoclonal antibody (mAb) Atezolizumab causes a reduction of immunosuppressive signals within the tumor microenvironment (TME).