CD274 and lung cancer: For non–small cell lung cancer (NSCLC), treatment with pembrolizumab is limited to patients with tumours expressing PD-L1 assessed by immunohistochemistry (IHC) using the PD-L1 IHC 22C3 pharmDx (Dako, Inc.)companion diagnostic test, on the Dako Autostainer Link 48 (ASL48) platform.