A Phase III clinical trial of treating patients with residual invasive HER2-positive breast cancer using TDM-1 or trastuzumab indicated that the disease-free survival was significantly higher in the T-DM1 group than in the trastuzumab group (HR, 0.5; 95% CI, 0.4 to 0.6; P<0.001) [28]. Here, ERBB2 is linked to breast cancer.