PDCD1 and neoplasm: The images were optimal at 1 h after injection, with the highest uptake ratio of tumor-to-muscle being 11.4±0.29 (In Figure 3B), In tumor–bearing mice pretreated with Sindilizumab (10mg/kg) for 24 h, the tumor uptake of 68Ga-NOTA-Nb109 was still observed, proving that Anti-PD1 treatment did not affect the specific binding of 68Ga-NOTA-Nb109 with PD-L1.