In particular, patients with TP53mut tumors showed a significant survival disadvantage in the hormone receptor+/HER2– BC subtype for both early (HR, 1.51 [95% CI, 1.24 to 1.85]; P < .0001) and advanced stages (HR, 1.90 [95% CI, 1.42 to 1.56]; P < .0001). This evidence concerns the gene ERBB2 and breast cancer.