Although the membrane‐positive expression of MIB‐1 has also been reported in breast cancer [17, 18], salivary gland pleomorphic adenoma [19], sclerosing haemangioma of the lung [20, 21], renal oncocytoma, and sarcomatoid pleural mesothelioma [10], these patterns were not clinically significant or reproducible. Here, MIB1 is linked to breast cancer.