Programmed cell death 1 (PD-1) and programmed death ligand 1 (PD-L1) are checkpoint proteins on immune cells responsible for the induction and maintenance of immune tolerance within the tumor microenvironment. Research studies have found that tumors tend to evade host defense mechanisms using these PD-1/PDL-1 pathways. PD-1/PDL-1 interaction act by inhibiting this binding and preventing tumor...