MKI67 and breast cancer: Gallen criteria used to define high-risk breast cancer are patient age < 35 years, tumour size >2 cm, tumour grade III, presence of extensive peritumoural vascular invasion, oestrogen receptor (ER) and/or progesterone receptor (PR) negativity, human epidermal growth factor receptor 2 (HER2) overexpression or HER2 amplification, high Ki67 expression (in grade II tumours) and >3 positive lymph nodes.