KRAS and pancreatic intraductal papillary-mucinous neoplasm: Siveke et al. established a mouse model by crossing Elastase-Rgfa mice with p48 (+/Cre); Kras (+/LSL-G12D) mice, in which concomitant expression of TGF-alpha and k-ras (G12D) led to development of cystic lesions resembling IPMN [59].