An interim analysis of the ongoing KATHERINE trial in patients with HER2-positive early breast cancer with residual invasive disease in the breast or axilla after neoadjuvant treatment with trastuzumab and a taxane revealed that use of adjuvant T-DM1 conferred a lower risk of recurrence of invasive breast cancer than adjuvant trastuzumab, although with a higher rate of adverse events.11 On the basis of these results, T-DM1 recently received regulatory approval for this neoadjuvant indication.12 Here, ERBB2 is linked to breast carcinoma.