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

Figure 4 Endogenous Kras^G12D plus transforming growth factor-β receptor 2 knockout pancreatic ductal adenocarcinoma. A, B: Macroscopic appearances and a survival curve of the endogenous Kras^G12D plus transforming growth factor-β receptor 2 (Tgfbr2) knockout pancreatic ductal adenocarcinoma (PDAC) mice; A: Abdominal distension and bloody ascites are observed. Black arrowhead indicates the tumor; B: The whole pancreas is occupied by tumor and enlarged (white arrowheads). Jaundice is also observed here; C-H: Microscopic appearance of the endogenous Kras^G12D plus Tgfbr2 knockout PDAC; C, D: Differentiated ductal adenocarcinoma with abundant stroma is observed in HE sections; E: Marked fibrosis and desmoplasia is observed. The blue color indicates fibrosis in trichrome blue staining; F: Positive immunostaining of cytokeratin 19 indicates a ductal phenotype tumor; G, H: The tumor has a metastatic potential to the lung (G) and liver (H).