Previously, mAbs targeting HER2/HER3, such as pertuzumab [118,125,126,127], trastuzumab [129,130], and seribantumab [133], showed some activity; however, their use is limited by the low frequency of HER2 overexpression and a lack of predictive biomarkers to select tumours that would be responsive. Here, ERBB2 is linked to neoplasm.