ERBB2 and breast cancer: Univariable analysis showed that in grade 1, 2 breast cancer patients, Ki-67 expression levels had a significant association with RFS in all patients (HR = 2.17, 95% CI: 1.53-3.06, p < 0.001) and in luminal-like patients (HR = 2.04, 95% CI: 1.31-3.30, p = 0.002), but not in HER2-positive (HR = 1.52, 95% CI: 0.80-2.91, p = 0.204) and TNBC (HR = 2.82, 95% CI: 0.59-13.34, p = 0.192) patients.