PD-1 and PD-L1 immunostaining of samples from the NKI-AVL cohorts were performed on fresh-cut slides from FFPE blocks using an anti–PD-1 antibody (NAT105, Roche Diagnostics) and anti–PD-L1 antibody (22C3 DAKO, Agilent) on a BenchMark Ultra autostainer Instrument (Ventana Medical Systems) as described previously (7 (link)). PD-L1 immunostaining of samples from the CERTIM cohort was performed using a different anti–PD-L1 antibody (E1L3N, Cell Signaling Technology, catalog No. AB_2687655) on a Bond automat (Leica Biosystems) as described previously by Adam and colleagues (14 (link)).
PD-1 IHC slides were scanned at 20× magnification with a resolution of 0.50 per μm2 using an Aperio slide AT2 scanner (Leica Biosystems).
PD-1 IHC slides were scanned at 20× magnification with a resolution of 0.50 per μm2 using an Aperio slide AT2 scanner (Leica Biosystems).
