We next used Univariate Cox regression analysis to calculate the hazard ratio (HR) of 26 HRGs, and the results showed that CA9, PGK1, and SDC1 (HR > 1.0, P < 0.05), were significantly associated with the OS of BC patients (Figure 3(a)), indicating that these three genes were risk genes, and their high expression was associated with poor prognosis. The gene discussed is CA9; the disease is breast cancer.