Schematic representation of the role of MYC as a reversible driver of cell-intrinsic and cell-extrinsic PDAC progression. Epithelial acinar-to-ductal metaplasia (ADM), pancreatic intraepithelial neoplasia (PanIN), progression to pancreatic ductal adenocarcinoma (PDAC), and reversion to PanIN and ductal-to-acinar transdifferentiation (DAT) are indicated. Desmoplastic stromal and vascular changes and immune cell infiltrates are depicted. ECM, extracellular matrix; KRAS*, mutationally activated KRAS.