Bruceine H, a derivative of Brucea javanica (L.), was found to overcome resistance to receptor tyrosine kinase (RTK)‐EGFRi in non‐small cell lung cancer (NSCLC) models by suppressing Notch3, EGFR activation and β‐catenin expression., thereby increasing gefitinib response. The gene discussed is NOTCH3; the disease is lung cancer.