Importantly, CD24 expression retained its statistical significance for OS (HR = 1.39, 95% CI = 1.04–1.87, P = 0.026) and marginal significance for DFS (HR = 1.28, 95% CI = 0.96–1.71, P = 0.090) at the multivariate level, indicating the CD24 overexpression is an independent negative prognostic factor in breast cancer (Table 3). Here, CD24 is linked to breast cancer.