IHC analysis demonstrated that the pancreatic malignant lesions in PKT mice were positive for the epithelial markers cytokeration-19 (CK19) and E-cadherin, and, in particular, tumor cells increased staining for the cell proliferation marker Ki67 were higher in PKT lesions than in the age-matched PK mice (Fig. 2d). This evidence concerns the gene MKI67 and neoplasm.