We blocked the secretion of exosomes by conditionally knocking out (KO) Rab27a in the healthy pancreas (Pdx1-Flp; Rab27aFrt/Frt) and in PDAC cancer cells using the fast progression PDAC model (PKT iRab27a, Ptf1a-Cre; LSL-KrasG12D/+; Tgfbr2loxP/loxP; R26LSL-FLPoERT2/+; Rab27aFrt/Frt). Here, PTF1A is linked to cancer.