Besides, we also performed the genomic alteration analysis, prognosis analysis, gene set enrichment analysis (GSEA), and immune cell infiltration analysis of SNAI2 in pan-cancer, the most interesting finding is that SNAI2 is a robust prognostic biomarker for pan-cancer and predict the immunotherapy response effectively, and provided the main thread for further investigation on the role of SNAI2 in cancer immunity. The gene discussed is SNAI2; the disease is cancer.