KRAS and pancreatic neoplasm: In KRAS G12V as well as KRAS/P53 mouse models of pancreatic cancer, it was found that mice treated with nicotine for 86 weeks had increased incidence of low grade PanIN lesions and increased acinar-to-ductal metaplasia with atrophy compared to control mice; furthermore, only mice treated with nicotine developed high grade PanIN lesions [45].