TTF1 and adenocarcinoma: Immunostaining for TTF-1, a marker of adenocarcinoma, and Sox2, a marker present in early lesions originating from CC10-positive cells and lost in advanced adenocarcinoma [40], revealed no difference between K-RasLSL-G12D/+;Lmo4fl/fl and K-RasLSL-G12D/+ mice (Fig. 5d).