Although based on the expression of estrogen receptor, progesterone receptor (PR), human epidermal growth factor receptor 2 (HER2) and Ki67, the molecular classification of BrCa (luminal A, luminal B, HER2 positive and triple negative) has provided considerable benefits3, many patients with BrCa experience metastasis or recurrence. The gene discussed is MKI67; the disease is invasive breast carcinoma.