In order to explore the prognosis of TMPRSS2 expression levels in different cancers based on immune cells, we analyzed the Kaplan-Meier plotter database and found that high expression of TMPRSS2 in breast cancer had a poor prognosis in enriched CD4+ T cells and enriched CD8+ T cells (Figures 5A, C), and high expression of TMPRSS2 in LUAD has a better prognosis in enriched B cells, enriched macrophage cells, and enriched CD4+ T cells, respectively (Figures 5E, G, I). The gene discussed is CD8A; the disease is cancer.