Genetically-engineered mouse models for pancreatic cancer: Advances and current limitations

Figure 3 Pancreas epithelium-specific Kras^G12D expression. Cre recombinase is expressed under the promoter of PDX1 or Ptf1a gene, which is pancreas epithelium-specific. Without cre recombinase expression, a stop sequence between the loxP sites prevents mutant Kras^G12D expression. In cells where only cre recombinase is expressed, the stop sequence is cut out, which turns on the pancreas epithelium-specific Kras^G12D expression at a physiological level under the native Kras promoter.