EGFR and cancer: In a pilot screen of 8,960 molecules, chemicals such as AG1478, which share a common backbone structure with gefitinib and erlotinib, as well as a MEK inhibitor, U0126, inhibited the Muv phenotype of jgIs6. We also provide evidence that MEK inhibitors may be effective in treating cancers that are resistant to known EGFR-TKIs.