CDKN2A and neoplasm: An important point is that, although all pancreatic cells in KIC mice express KrasG12D and have inactivated Cdkn2a (indeed, p48::Cre drove TdTomato expression throughout the pancreas; supplementary material Fig. S3), Rgs16::GFP is absent at P15 except for expression in the earliest lesions, and then throughout tumor progression.