As example, trastuzumab and pertuzumab (mAbs) on the one hand, and lapatinib and neratinib (small molecules) on the other, all targeting and interfering with the human epidermal growth factor receptor 2 (HER2), have shown to be beneficial for treating patients affected by a subtype of breast cancer overexpressing HER2 [15]. Here, ERBB2 is linked to breast cancer.