Osimertinib-associated cardiac toxic effects, including arrhythmia, cardiac dysfunction, progression of valvular heart disease, and myocardial infarction, have been reported.18,19 However, whether osimertinib carries a higher incidence of cardiac toxic effects compared with other EGFR TKIs remains a topic of debate. The gene discussed is EGFR; the disease is cardiac arrhythmia.