Fig. 4

Comparison of tumor proportion scores (TPS) for PD-L1 expression between immunohistochemical (IHC) single and double staining. Double staining results in a lower TPS for PD-L1 expression compared with single staining. IHC single staining was performed using a VENTANA PD-L1 (SP263) Rabbit Monoclonal Primary Antibody assay. IHC double staining was performed using an automated Ventana IHC assay for TTF-1 (dilution 1:100; SPT24 clone, Leica, USA) with an ultraView Universal AP Red Detection Kit (Ventana Medical Systems, Tucson, AZ) on the basis of the IHC PD-L1 single-staining process