An irreversible dual inhibitor of EGFR and HER2 (IC50s = 34 and 33 nM, respectively); inhibits proliferation of A431, SK-BR-3, and SW620 cancer cell lines (IC50s = 120, 2.5, and 511 nM, respectively); suppresses EGFR autophosphorylation and phosphorylation of the downstream effectors AKT and ERK in NCI-H1650 and NCI-H1650(G7) cells; inhibits tumor growth in BT474, A431, and SUM190 mouse xenograft models (10 mg/kg) ,