ERBB2 and breast cancer: In the present study, we found that the NQO1 expression level was markedly associated with histological grade (P = 0.004), clinical stage (P = 0.008), LN metastasis (P = 0.005) and Her2 expression levels (P = 0.019), suggesting that NQO1 upregulation promotes the invasion and/or metastasis of breast cancer cells.