The list of Mut-driver genes includes well-established breast cancer oncogenes and tumour suppressors such as PIK3CA and TP53. TP53, categorized as a tumour suppressor, had high ONC and TSG scores in both ER+ (ONC=42%, TSG=35%) and ER− (ONC=45%, TSG=40%) tumours. The gene discussed is ESR1; the disease is breast cancer.