Interestingly, AT2 proliferation is selectively induced by Cre-regulated oncogenic Kras-G12D in vivo (Jackson et al., 2001), efficiently generating multifocal, clonal adenomas in the lungs with replacement of almost the entire alveolar region and death of the animals within a month after birth (Desai et al., 2014). This evidence concerns the gene KRAS and adenoma.