For example, trastuzumab is used for HER2-amplified breast cancer BrM, tragisso (Osimertinib) for EGFR-mutant lung cancer BrM [14,15], and xalkori (Crizotinib), alecensa (Alectinib), alunbrig (Brigatinib), and zykadia (Ceritinib) against ALK-rearranged BrM [4,15,16,17,18,19,20,21]. The gene discussed is ERBB2; the disease is breast cancer.