We showed that a Rgs16::GFP transgene is an in vivo reporter of Kras activity in precancerous pancreatic neoplasia, including pancreatic intraepithelial neoplasia (PanIN), intraductal papillary mucinous neoplasm (IPMN), and throughout PDA tumor progression in KIC;Rgs16::GFP mice (p48Cre/+; KrasG12D/+; Cdkn2af/f; Rgs16::GFP)22. Here, KRAS is linked to Patent ductus arteriosus.