SMAD4 and pancreatic neoplasm: The currently available porcine pancreatic cancer cell lines (i.e., PGKP, PGKPS, and PGKPSC) were generated from primary pancreatic ductal cells obtained from domestic pigs via the expression of oncogenic K-rasG12D and p53R167H, with or without knockdown of p16Ink4A and SMAD4 [30].