CD274 and neoplasm: As shown in Figure 5, the MC38-B7H1 tumor (PD-L1-positive) was clearly visualized at 2 h p.i. After coinjection with cold WL12 peptide, the tumor was almost invisible, which was consistent with the trend observed in the biodistribution results, suggesting that [99mTc]Tc-HYNIC-WL12-tricine/ISONIC is worthy of further preclinical development.