Furthermore, patients with higher SIX4 level tended to display worse OS (HR: 1.39, 95% CI: 1.04–1.86; P = 0.770 and I2 = 0.0%; Supplementary Figure 5A) of whole breast cancer population, while did not exhibit significant difference on RFS (HR: 1.24, 95% CI: 0.80–1.92; P = 0.689 and I2 = 0.0%; Supplementary Figure 5B) and MFS (HR: 0.84, 95% CI: 0.59–1.20; P = 0.266 and I2 = 24.3%; Supplementary Figure 5C). The gene discussed is SIX4; the disease is breast cancer.