PDX1 and pancreatic neoplasm: KPC mice carrying a knock-in allele of LSL-KrasG12D and a “floxed” allele of Tp53fl/fl in combination with the pancreas-selective Pdx1-Cre transgene is a commonly used genetic murine model for human pancreatic cancer [26] which recapitulates the cardinal features of the human disease including resistance to chemotherapy and development of dense desmoplastic stroma surrounding the carcinoma cells.