Obviously, the high expression of TMPRSS2 showed a poor prognosis in breast cancer (OS HR = 0.88, 95% CI = 0.78 to 0.98, p = 0.021) (Figure 2A), while it showed favorable prognosis in lung cancer, ovarian cancer, and gastric cancer (OS HR = 0.71, 95% CI = 0.62 to 0.8, p = 9.7e-08; OS HR = 0.77, 95% CI = 0.68 to 0.87, p = 3.8e-05; OS HR = 0.74, 95% CI = 0.63 to 0.88, p = 0.0057 respectively) (Figures 2B–D). The gene discussed is TMPRSS2; the disease is lung cancer.