Most recent are targeting two immuno-checkpoint receptors; CTLA4 (cytotoxic T-lymphocyte-antigen 4), PD-1 (programmed cell death 1) and its ligand PDL1, and show a remarkable efficacy against certain tumors, through re-activating cytotoxic T (Tc) cell mediated tumor killing [5, 6]. The gene discussed is PDCD1; the disease is neoplasm.