HER2-high breast cancer (BC) patients had received prior trastuzumab and T-DM1 (100%), pertuzumab (82%) and lapatinib (53%), with a median of six HER2-targeted regimens for metastatic disease, whereas all gastrointestinal patients had received prior trastuzumab, with a median of four lines of treatments. Here, ERBB2 is linked to breast carcinoma.