More recently, data from the adjuvant trastuzumab emtansine versus paclitaxel in combination with trastuzumab for stage I HER2-positive breast cancer (ATEMPT) study demonstrated that, among patients with stage I HER2-positive breast cancer, 1 year of adjuvant T-DM1 was associated with a 3-year invasive disease-free survival rate of 97.8% (95% confidence interval [CI]: 96.3–99.3%)14. Here, ERBB2 is linked to breast cancer.