The embryonic development of all body systems is controlled by coordinated interactions of a group of genes encoding master regulators of development, which determine the fate of cells in the process of differentiation. These genes are often involved in the processes of malignant degeneration of cells. Hence, they are considered as targets of targeted gene therapy in the development of modern approaches to cancer treatment. One of the most aggressive forms of cancer is pancreatic ductal adenocarcinoma (PDAC). Thus, the study of pancreas master regulators genes is a challenging task. This review is devoted to SOX9, which is one of the key master regulators of pancreatic development and is a crucial factor in the induction and progression of PDAC.