The programmed cell death protein 1 (PD-1)/programmed cell death ligand 1 (PD-L1) pathway is an immune checkpoint pathway that suppresses immune system activation, where binding of the T cell receptor PD-1 to its ligand PD-L1 leads to downregulation of T cell proliferation, activation, and host anti-tumor function [10]. This evidence concerns the gene CD274 and neoplasm.