Fig. 4

Flow cytometry evaluation of the bindings of coumarin-containing nanoparticles to various cells. A PD-L1-positive CT26 cells, B PD-L1-positive MDA-MB-231 cells, C PD-L1-negative A549 cells, D Activated PBMCs with high PD-1 expression, and E Fresh PBMCs with low PD-1 expression