A selective EGFR-TK inhibitor that blocks the growth of GEO colon cancer, ZR-75-1 and MCF-10A Ha-ras breast cancer, and OVCAR-3 ovarian cancer cell lines (IC50s = 0.2-0.4 µM); interferes with the intracellular kinase domain of the EGFR; used to treat advanced (or recurrent) non-small cell lung cancer.