KRAS and adenocarcinoma in situ: Hematoxylin and eosin (H&E) staining of the lungs revealed the presence of adenocarcinoma in situ, carcinomas, and invasive adenocarcinoma lesions in both KRAS G12D eIF2αS/S and eIF2αA/A mice20; these lesions were larger in eIF2αS/S than eIF2αA/A lungs (Fig. 2d).