According to the univariate log-rank analysis, we found lymph nodal infiltration (p = 0.000), tumour size of pT3-pT4 (p = 0.000), and low total cellular HER3 protein expression (p = 0.004) as strong indicators of shortened RFS in HER2-amplified breast cancer (Table 7, Fig. 4). This evidence concerns the gene ERBB3 and breast cancer.