ERBB2 and triple-negative breast carcinoma: In a study by Schettini et al. evaluating 3689 patients, it was observed that low HER2 expression was more frequent in HR-positive disease than in triple-negative breast cancer (TNBC) (65.4% vs 36.5%, p < 0.001), and HER2-low patients were significantly associated with more nodal involvement and a larger primary tumor diameter compared to HER2-zero [5].