Studies of pancreatic ductal adenocarcinoma (PDA) have mostly used mouse models that express oncogenic KRAS in all cells of the pancreas. As such, not much is known about the PDA cell-of-origin. Kopp et al. have labelled and traced specific cell populations in the mouse pancreas following KRAS activation and discovered that acinar cells form PDA precursor lesions, whereas ductal and centroacinar cells do not. Lesion formation from acinar cells was dependent on the expression of the ductal fate determinant gene Sox9, indicating that a duct-like state is induced in these cells. Understanding this reprogramming pathway could aid the early detection of PDA and could provide new opportunities for therapies.