Gruber et al1 demonstrate that YAP/TAZ activity is critical for acinar ductal metaplasia (ADM) by crossing conditional knock-out mice with the well-studied LSL-Kras model of PDAC. They also provide evidence that YAP/TAZ may be sufficient, because ectopic expression of YAP/TAZ using adenoviral vectors led isolated acinar cells to undergo ADM in vitro. The JAK-STAT3 pathway was found to be critically involved in the actions of YAP/TAZ leading to ADM. These observations add to our understanding of the mechanisms involved in this crucial early step in the development of pancreatic cancer.