Summary of the validation on tissue microarrays of the programmed death ligand 1 (PD-L1) SP263 clone on Ventana BenchMark against the Dako PD-L1 22C3 clone on the Dako Autostainer Link 48 in (A) lung adenocarcinomas and (B) squamous cell carcinomas. A very high level of concordance was observed. For adenocarcinomas, there were 111 of 113 tissue microarray (TMA) cores (98%); and for squamous cell carcinomas, there were 100 of 103 TMA cores (97%). (C) For (i) 22C3 and (ii) SP263 there is no PD-L1 expression in lung adenocarcinoma, whereas (iii) 22C3 and (iv) SP263 show comparable expression of more than 50% on tumor epithelium in a squamous cell carcinoma. And in (v) 22C3, two or three tumor epithelial cells are expressing PD-L1, but this expression was not observed in a serial core with the SP263 clone (vi).