Using phage display technique, Chang et al. reported a D-form peptide DPPA-1 (NYSKPTDRQYHF), which had a high affinity to PD-L1 with a KD value of 0.51 μM measured by surface plasmon resonance (SPR), and DPPA-1 at 2 mg/kg inhibited the tumor growth in CT26 tumor-bearing mice and prolonged their survival time to nearly 50% longer [41]. Here, CD274 is linked to neoplasm.