To date, five mAbs have been clinically approved and target different ErbB family members: EGFR (HER1): cetuximab (2004, head and neck and colorectal cancers), panitumumab (2006, colorectal cancer), necitumumab (2015, non-small lung cancer); and HER2: trastuzumab (1998, breast cancer) and pertuzumab (2012, breast cancer) [14, 19–26]. The gene discussed is ERBB2; the disease is breast carcinoma.