The SCLC liver metastasis exhibited a lower proportion of CD8+ T cells (SCLC liver CD8+ proportion 0; TRACERx EGFR mutant cohort median = 0.054, IQR = 0.037–0.071) and higher proportions of immunosuppressive M2 macrophages (SCLC liver M2 macrophages proportion 0.34; TRACERx EGFR mutant cohort median = 0.21, IQR = 0.18–0.24; Extended Data Fig. 8c). This evidence concerns the gene EGFR and metastasis.