CD274 and neoplasm: In this study, the tumor cells, T cells, and vessels were labeled in vivo by intravenously injected Erbium-based rare-earth nanoparticles (ErNPs) conjugated to anti-PD-L1 antibody, PEGylated PbS/CdS core/shell quantum dot (CSQD) conjugated to anti-PD-1 antibody, and p-FE (comprised of organic dyes trapped in amphiphilic polymeric micelles approximately 12 nm in size), respectively.