EGFR and cancer: Method. We selected six EGFR/ERBB2-amplified cancer cell lines (OE19, NCI-N87, OE33, ESO26, MKN7, and BT474) as an in vitro model and tested their sensitivity to DF alone and to DF in combination with the well-known EGFR/ERBB2-targeting reagent lapatinib.