PD1-tumor-peptides Published June 18, 2019 at 1728 × 845 in How to Identify a PD-L1 Binding Peptide for Determination of PDL1 Expression in Tumors How to Identify a PD-L1 Binding Peptide for Determination of PDL1 Expression in Tumors Blocking the interaction between Programmed Death Ligand 1 (PD-L1) and its receptor, PD-1, is an effective method of treating many types of cancers.