Cell signaling through the PD-1 receptor upon binding the PD-L1 ligａnd attenuates immune responses and this pathway is exploited by both tumors and viruses. The Monkey PD-1:PD-L1[Biotinylated] Inhibitor Screening Assay Kit is designed for screening and profiling inhibitors of this signaling pathway in the animal model cynomolgus monkey (Macaca fascicularis).