Consistent with the flow cytometryresults, tumor immunohistochemistry (IHC) staining of the PD-L1 markerrevealed that the OxPt/SN38 group had a much higher PD-L1 expressionlevel than the PBS group while the PD-L1 expression level in the OxPt/SN38plus αPD-L1 group was lower than those in both PBS and freedrug combination groups (Figure 5m). This evidence concerns the gene CD274 and neoplasm.