Considering the discrepancy between HR-positive and HR-negative breast cancers in terms of both molecular nature and clinical management, we stratified patients by HR status to characterize HER2-low breast cancers among luminal and triple-negative breast cancers (TNBCs) separately, and no significant differences were found regardless of HR status in terms of clinicopathological characteristics (Table 1). This evidence concerns the gene ERBB2 and breast carcinoma.