PDX1 and pancreatic neoplasm: To identify a gene expression ‘signature’ specific to these mice, principal component analysis (PCA) was used to compare the transcriptome of these tumours with those arising in other mouse models of pancreatic cancer, notably KPC,17, 18Pdx1-Cre, KrasG12D/+ Lkb1fl/+20 and Pdx1-Cre, KrasG12D/+ Apcfl/+ mice (figure 5D).