Immunohistochemical analysis of β-galactosidase expression in the oral mucosa of K-ras+/G12D; Rosa+/CreERT2; Rosa+/R26R mice dosed with 1 mg of tamoxifen at 8 weeks of age showed oral squamous hyperplasia, papilloma formation, and dysplastic papilloma (with irregular basal aspect) with strong β-galactosidase expression in stromal cells as well as in the squamous epithelium (Figures 1H and 1I and Supporting information, Supplementary Figure 2). The gene discussed is KRAS; the disease is papilloma.