Fig. 4

Cell affinity characteristics of ¹³¹I-PD-L1-Mab in vitro. a Cell binding of ¹³¹I-PD-L1-Mab to four different CRC cell lines with constant concentration of ¹³¹I-PD-L1-Mab. b Cell binding of ¹³¹I-PD-L1-Mab to RKO with or without blocking. c Saturation binding assay of ¹³¹I-PD-L1-Mab, Kd = 1.069 nmol/L, the number of binding sites was 113,671 ± 4183 per cell. d Competitive inhibition assay of ¹³¹I-PD-L1-Mab showed an IC50 of 252.1 nmol/L. The data are expressed as means ± SD, *** p < 0.001