Risk stratification is particularly relevant in patients with oestrogen receptor (ER)-positive/human epidermal growth factor receptor 2 (HER2)-negative tumours, since high-risk (NHG3) patients will typically be provided chemotherapy in addition to endocrine therapy, and low-risk (NHG1) patients would be spared chemotherapy in order to avoid overtreatment, whereas the intermediate NHG2 group is uninformative and has limited clinical value for treatment decisions. Here, ERBB2 is linked to neoplasm.