Figure 6. Internal validation of TfR1 as an independent prognostic factor for BC patients. (A) Univariate and multivariate Cox regression analyses determined TfR1 as an independent prognostic factor. (B) A prognostic nomogram integrating TfR1 expression and clinicopathologic variables was constructed to estimate OS. (C) Calibration plots to predict the OS of BC patients at 1, 3, and 5 years.