PGK1 and breast cancer: 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.