PDX1 and pancreatic neoplasm: NNK exposure to KC (LSL-KrasG12D/+;Pdx-1-Cre) mice, which are predisposed to spontaneous pancreatic intraepithelial neoplasia (PanIN) and pancreatic cancer development, resulted in increased mean pancreatic weights compared to mice receiving simultaneous NNK and broad-spectrum antibiotic treatment (Figure 1E).