In a univariate analysis, the number of positive SLNs (P < 0.001), the SLN metastasis rate (P < 0.001), LVI (P=0.017), HER2 overexpression (P=0.006), and IHC-based subtype (P=0.05) were all significantly related to N2 disease status in these BC patients (Table 3). Here, ERBB2 is linked to breast cancer.