Immune checkpoint blockade (ICB) therapy aims to interrupt immunosuppressive tumor signals and restore anti-tumor immune responses by targeting checkpoint receptors or ligands, such as PD-1 (programmed cell death protein 1) and its ligand PD-L1, CTLA-4 (cytotoxic T lymphocyte-associated protein 4), LAG-3 (Lymphocyte-activation gene 3), and TIGIT (T-cell immunoreceptor with Ig and ITIM domains) (43, 44). This evidence concerns the gene PDCD1 and neoplasm.