Moreover, studies have shown that PD-L1 is overexpressed in MDSCs and plasmacytoid dendritic cells (pDCs), and the subsequent blockade of the PD-1/PD-L1 axis leads to a reversal of the immunosuppressive effect of MDSCs and increased generation of cytotoxic T cells by pDCs, which ultimately leads to an increased anti-tumor immunity [7,8]. This evidence concerns the gene CD274 and neoplasm.