The pancreatic and duodenal homeobox 1 gene (PDX1) encodes a specific transcription factor that regulates pancreatic development and β-cell-specific gene expression. It is also the first molecular marker during pancreatic stem cell differentiation and maturation. In this model, the ‘P2A-CreERT2’ cassette is inserted upstream of the TGA stop codon in the mouse Pdx1 gene. When Pdx1-CreERT2 mice are crossed with mice containing loxP sites, tamoxifen induction can trigger sequence recombination between the loxP sites mediated by Cre recombinase in the pancreas of the offspring. It’s important to note that some leaky expression of CreERT2 recombinase may be observed without tamoxifen treatment.