Expression of Programmed Cell Death-1 (PD-1) and Its Ligand (PD-L1) in Breast Cancers and Its Association with Clinicopathological Parameters.

 Cancer immunotherapy targeting the programmed cell death ligand 1 (PD-L1) and programmed cell death-1 (PD-1) axis has revolutionized cancer therapy. PD-L1 also serves as a predictive marker for such therapy. To assess the potential of such therapy in any cancer, the positivity of PD-1 and PD-L1 in such cancers needs to be assessed.