Ets1 and Zeb1 are expressed at the invasive front of K-Ras initiated mouse lung adenocarcinoma. (A and B) H&E staining showing the invasive front of an adenocarcinoma (AC) from a K-RasLA1 mouse lung. (C-E) Note immunostaining for E-cadherin (E-cad.) in normal lung and expression of Zeb1 and Est1 in carcinoma invading into normal lung. Arrows indicate invasive carcinoma.