GSEA results showed that top four high Lgals9-related enrichment pathways in SCLC were “KEGG_PRIMARY_IMMUNODEFICIENCY”,“KEGG_SYSTEMIC_LUPUS_ERYTHEMATOSUS”, “KEGG_ALLOGRAFT_REJECTION”, and “KEGG_GRAFT_VERSUS_HOST_DISEASE”, with 18 Lgals9-related DEGs. This evidence concerns the gene LGALS9 and small cell lung carcinoma.