showed that a 64-year-old woman was diagnosed with metastatic lung adenocarcinoma harboring an EGFR mutation; 2 months after osimertinib initiation, which revealed that her left ventricular systolic function was depressed, with a globally reduced ejection fraction of 24%, they concluded that the heart failure had been caused by osimertinib inhibiting human epidermal growth factor receptor 2 (HER2) (22). The gene discussed is ERBB2; the disease is heart failure.