In addition to dysfunctional stromal cells in the tumor microenvironment, there are also various regulatory T-cells, myeloid-derived suppressor cells, and up-regulated tumor suppressor molecules such as cytotoxic T-lymphocyte-associated antigen-4 (CTLA-4) and programmed cell death protein-1 (PD-1) [5, 6]. This evidence concerns the gene PDCD1 and neoplasm.