PRDX1 and invasive ductal breast carcinoma: Notably, biomarker studies have confirmed that PRDX1 is one of the diagnostic biomarkers for invasive ductal carcinoma of breast with human epidermal growth factor receptor‐2 (HER2)‐enriched subtypes 59, and PRDX1 protects ERα from oxidative stress‐induced suppression and is a protein biomarker of favourable prognosis in mammary tumours 60.