T cells from both NATs and the TME were mainly composed of CD8-positive T cells and expressed high levels of cytotoxic markers, such as GZMA/B/H/K, PRF1, NKG7, IFNG, GNLY and CXCL13, implying significant immune surveillance in SCLC (Supplementary Fig. S2a). This evidence concerns the gene GZMA and small cell lung carcinoma.