IC such as programmed cell death protein 1 (PD-1), programmed death-ligand 1 (PD-L1), cytotoxic T-lymphocyte associated protein 4 (CTLA-4), T cell immunoglobulin and mucin-domain containing-3 (TIM-3), and lymphocyte-activation gene 3 (LAG-3) are immune regulators that can trigger immune escape by promoting tumor progression and inhibiting effective immune responses [13,14]. The gene discussed is PDCD1; the disease is neoplasm.