ERBB2 and breast cancer: Contrary to our previous OS findings, the multivariate analysis revealed that breast cancer patients with HER2-low tumors do not experience better outcomes compared to those with HER2-positive (HR = 0.69, 95% CI, 0.30–1.61, p = 0.403) or HER2-negative tumors (HR = 0.57, 95% CI, 0.30–1.09, p = 0.092).