A recent study found that mubritinib, a Food and Drug Administration (FDA) approved drug initially used as a human epidermal growth factor receptor 2 (HER2) inhibitor, could significantly reduce the development of leukemia through inducing mitochondrial respiration‐associated ROS overproduction and cell apoptosis instead of targeting HER2 protein.7 The gene discussed is ERBB2; the disease is leukemia.