CD274 and small cell lung carcinoma: To orthogonally assess tumor-infiltrated T cells, we performed immunohistochemistry (IHC) by T-cell marker CD3 and programmed death ligand-1 (PD-L1) (Supplementary Fig. 14) on 66 SCLC tumors, including 18/19 tumors in the current study (one tumor tissue was exhausted) and 68 NSCLC tumors (Supplementary Data 1) with matched clinical characteristics, including sex, age, smoking status and tumor size (Table 1).