ERBB2 and breast cancer: There are eight clinical trials associated with the therapeutic effects evaluation of trastuzumab emtansine in HER2-positive breast cancer patients (Burris et al., 2011; Krop et al., 2012; Verma et al., 2012; Hurvitz et al., 2013; Krop et al., 2014; Diéras et al., 2017; Krop et al., 2017; Perez et al., 2017), and the most cited one was a phase 3 clinical trial, which demonstrated that T-DM1 prolonged progression-free survival of breast cancer patients who had been previously treated with trastuzumab and a taxane (Verma et al., 2012).