CTLA4 and neoplasm: In addition, these IgG1 monoclonal antibodies can elicit antibody-dependent cellular cytotoxicity (ADCC) and complement-dependent cytotoxicity (CDC) against PD-L1-expressing tumor cells and CTLA-4-expressing regulatory T cells, thereby enhancing the release of tumor antigens and reducing immunosuppression in the TME [38,39,40].