ERBB2 and breast cancer: In molecular subgroup analyses, high-grade TB was related to poor outcomes in patients with HER2-positive tumors (p < 0.001) (Figure 2H), luminal A tumors (p = 0.038) (Figure 2I), and triple-negative BC (TNBC) tumors (p = 0.028) (Figure 2J), but not in luminal B subtypes (p = 0.237) (Supplementary Figure S1).