PTF1A and pancreatic neoplasm: Exosomes derived from normal fibroblast-like mesenchymal cells carrying siRNA or shRNA specific to KrasG12D (named iExosomes) (Fig. 2) suppress pancreatic cancer progression and extend mouse survival in Pdx1-Cre; lox-stop-lox-KrasG12D/+; lox-stop-lox-Trp53R172H/+ (KPC) and Ptf1a-Cre; lox-stop-lox-KrasG12D/+; Tgfbr2lox/lox genetically engineered pancreatic cancer mouse models [65].