An active UPR thus provides a survival advantage to cancer cells over normal cells and the analysis presented in this manuscript showed the association between BiP expression and HER2 and basal molecular subtypes (usually more aggressive than luminal-like tumors), and its association with metastasis and short relapse-free survival highlights the prognostic potential of BiP for breast cancer as an indicator of poorer outcomes. This evidence concerns the gene ERBB2 and breast cancer.