MKI67 and breast cancer: SHON nuclear expression was associated with favourable clinicopathological features including hormone receptor (ERα+, PR+ and AR+) positivity, 4-IHC luminal A (ERα+/HER2−/low proliferation phenotype), tubular BC, low histological grade, low mitotic index, low proliferation index (Ki67), low pleomorphism, and MDM4 overexpression (Table 1).