CD274 and small cell lung carcinoma: In contrast, trials evaluating immune checkpoint inhibitors (ICIs) included patients with more advanced disease stages, such as stage IV non-squamous NSCLC, extensive stage small cell lung cancer (ED-SCLC), locally advanced or metastatic NSCLC with PD-L1 expression, recurrent or metastatic head and neck squamous cell carcinoma (HNSCC), advanced urothelial cancer, unresectable or recurrent gastric/gastroesophageal junction (G/GEJ) cancer, and wild type metastatic NSCLC (Figure 5).