Characteristics of spontaneous HPV buccal tumors. Characteristics of spontaneous HPV buccal tumors. A, Representative pictures of gross buccal tumors arising from oncogene cotransfection in C57BL/6NCr mice. Plasmids contained HPV16-E6/E7, luciferase, NRasG12V, and SB100. B, Representative histology sections with H&E stain and special IHC staining with Ki-67 and NRas. C, Representative images for RNAscope targeting HPV16 RNA and IHC staining with HPV-associated biomarker p16. Three independent experiments were performed. Yi-Hsin Lin et al. Cancer Immunol Res 2018;6:305-319 ©2018 by American Association for Cancer Research