ERBB2 and breast cancer: An analysis of 28,280 patients with early breast cancer by Tan et al., showed that the outcomes for patients with HER2-low breast cancer were better than for those with HER2-zero disease, including recurrence-free interval (Hazard ratio 0.88, 95% CI 0.82–0.93, p = 0.001) and OS (Hazard ratio 0.82, 95% CI 0.76–0.89, p = 0.001); these differences were consistent irrespective of HR-expression [19].