ERBB2 and ductal breast carcinoma in situ: All patients were in their 40s, premenopause and carried Luminal A-like IDC (n = 3) (KU539, KU779 and KU957) or oestrogen receptor (ER) (+) human epidermal growth factor receptor 2 (HER2) (−) DCIS (n = 2) (KU582 and KU873) (Supplementary Table 1).