TGFB1 and familial pancreatic carcinoma: As loss of downstream TGFβ target SMAD4 is common in pancreatic cancer (Hahn et al., 1996), LSL-KrasG12D/+;Dpc4flox/+;Pdx1−Cre and LSL-KrasG12D/+;Dpc4flox/+;Ptf1aCre/+ were generated to conditionally express KrasG12D in concert with Smad4/Dpc4 haploinsufficiency in the pancreas, thereby inducing MCNs and subsequent PDAC (Izeradjene et al., 2007).