CD274 and hepatocellular carcinoma: In similar studies with MKN-45 cells PD-L1 concentrations (Bmax = 2155 sites per cell [Kd = 0.55 nmol/L]) were 25- to 12-fold lower than HCC-827 and MDA-MB231 cells, respectively, with the majority of the bound [89Zr]Zr-DFO- PD-L1 mAb representing nonspecific binding (52%-83%; Figure 1B; supporting information, Supplementary Figure S3).