To further extend our finding that the FOXO3a-BRD4-CDK6 axis promotes resistance of PI3K/AKT inhibition, we treated BT474 cells with Lapatinib (1 μM), which is an EGFR/HER2 dual tyrosine kinase inhibitor that is commonly used in breast cancer treatment. The gene discussed is PIK3CA; the disease is breast cancer.