Fig. 2.

a–d Intrinsic specificity of L2987 and KO cell lines: both E1L3N and 28-8 appear to be specific to PD-L1, as all staining is completely eliminated in the L2987 KO cell line. Both 28-8 and E1L3N were tested at 2 µg/mL. e–h Intrinsic specificity of ES-2 and KO cell line: both E1L3N and 28-8 appear to be specific to PD-L1, as all plasma membrane staining is eliminated in the L2987 KO cell line; however, some cytoplasm staining remains with E1L3N. 28-8 concentration was increased to 3 µg/mL so staining intensity was equivalent to E1L3N at 2 µg/mL. Ab antibody, KO knockout, PD-L1 programmed death-ligand 1