Tissue micro-arrays were constructed of ER+/PR±/HER2− (n = 37), ER−/PR−/HER2+ (n = 15), ER−/PR−/HER2− (n = 61) and ER+/PR+/HER2+ (n = 20) breast cancers; including 13 inflammatory breast carcinomas. This evidence concerns the gene ESR1 and breast cancer.