Combined with lapatinib, a Human Epidermal Growth Factor Receptor 2 (HER2)/EFR inhibitor, it reduces proliferation of HER2-positive breast cancer cells (BT-474, SKBR-3), reducing lapatinib dose (using 12 μM oleocanthal with 30 nM Lapatinib in BT-474 cells and 15 μM with 60 nM in SKBR-3) [95]. This evidence concerns the gene ERBB2 and breast cancer.