Via the transgenic expression of PDPN in Rip1Tag2 transgenic mice (expression of simian virus 40 large and small T antigens under the control of insulin promoters; mouse model of pancreatic β cell carcinogenesis), PDPN caused an acceleration of tumor progression with a higher incidence of tumor invasion and tumor malignancy, without the formation of lymph-node or distant-organ metastasis. Here, PDPN is linked to neoplasm.