Recent evidence has suggested that tumor-mediated immunosuppression by the up-regulation of coinhibitory immune checkpoints such as programmed death 1 (PD-1) and cytotoxic T-lymphocyte antigen 4 (CTLA-4) represent major obstacles to the generation and maintenance of clinically meaningful antitumor immunity [7, 8]. This evidence concerns the gene PDCD1 and neoplasm.