CD274 and lung cancer: It inhibits T lymphocytes expansion and produces cytokines like IL-2 and IFN-γ.18 Thus, anti-PD-1/ PD-L1 drugs studied against various malignancies are now undergoing clinical trials to treat lung cancer.19 CTLA-4, an immunological checkpoint and a homolog of T-cell CD28, is displayed as a cell membrane receptor on activated CD8 + and CD4 + T-cells.