Additional mouse models represent epidermal growth factor (EGFR) gene mutations known to be found in a subset of lung adenocarcinoma, but it is unclear if either of these models represent the early changes that are needed to progress to pre-malignant and ultimately malignant lung adenocarcinoma—particularly in tobacco smokers, who rarely harbor EGFR mutations [10]. The gene discussed is EGF; the disease is lung adenocarcinoma.