Abstract: This invention relates to a recombinant nucleic acid for an RIP-tk (rat insulin promoter-thymidine kinase) construct that selectively targets insulin secreting cells, such as ?-cells, PDX-1 positive human pancreatic ductal carcinomas, and other cells containing certain transcription factors. The present invention is useful in the treatment of pancreatic cancers, such as ?-cell insulinomas and can also be used to target pancreatic tumors that do not express insulin, such as pancreatic adenocarcinoma.