What we are striving for in cancer care today is personalized medicine. So, if a patient with newly diagnosed NSCLC has an activating epidermal growth factor receptor (EGFR) mutation, we give that patient Tarceva (erlotinib), a tyrosine kinase inhibitor (TKI). Right? Well, yes -- but it doesn’t always work (the response rate is in the 70-75% range). Why not? We’re not sure, but it would be nice to learn why we don't see near a 100% response rate among patients with EGFR mutations, so that we can know to recommend other alternatives.