ERBB2 and neoplasm: In our IHC‐based cohort involving 81 Chinese histologic grade III ER+HER2− patients, we found that non‐luminal‐like patients had larger tumor size, more metastatic lymph nodes, and worse DFS (multivariate HR non‐luminal‐like vs luminal‐like, 3.48, 95% CI, 1.17–10.42, P < 0.001) than those with luminal‐like tumors (Fig. 5J; Table S23).