Progress in molecular targeted drugs has prolonged survival (Li et al., 2023), particularly in patients with lung cancer harboring epidermal growth factor receptor (EGFR) mutations (i.e., erlotinib, gefitinib, afatinib, dacomitinib, and osimertinib) or anaplastic lymphoma kinase (ALK) rearrangement (i.e., ceritinib, alectinib, brigatinib, ensartinib, lorlatinib), and in patients with breast cancer harboring human epidermal growth factor receptor 2 (HER2) amplification (i.e., trastuzumab). The gene discussed is ERBB2; the disease is breast cancer.