PDCD1 and neoplasm: First, the upregulated PD-L1 in the tumor cells poses an extrinsic check over the tumor-infiltrating immune cells e.g. the TAMs and T-lymphocytes via engagement with PD-1 as the role of PD-L1/PD-1 ligation in suppressing immune responses of antigen-presenting cells and T-cells has been well established [1, 3].