Therefore, to ensure that tumor progression originated exclusively in pancreas tissue, the mice investigated in this study involved activation of the G12D Kras oncogene indirectly under the control of the Ptf1a promoter, and therefore the Ptf1aCre/+;LSL-KrasG12D/+ mouse strain was used as a model of human pancreatic cancer. Here, KRAS is linked to pancreatic neoplasm.