KRAS and pancreatic neoplasm: Genetically engineered mice that express oncogenic Kras in the pancreas develop PanINs that progress to pancreatic cancer (Aguirre et al., 2003; Hingorani et al., 2003; Hingorani et al., 2005), a process that is accelerated by the introduction of other common mutations, such as mutation or loss of tumor suppressors p53 and Ink4a/ARF (Aguirre et al., 2003; Hingorani et al., 2005).