Trastuzumab (Herceptin; Genentech, South San Francisco, CA) is an agent that competitively binds to the extracellular domain of HER2 and inhibits the HER2 signaling pathway.6 Flavonoids hesperetin and naringenin inhibit the HER2 activation pathway through the same action as lapatinib as a tyrosine kinase inhibitor.7 However, resistance of cancer cells to HER2-targeted agent was reported.6,8 It is important to investigate alternative agents that have a role in the HER2 pathway. Here, ERBB2 is linked to cancer.