PDX1 and pancreatic neuroendocrine tumor: The involvement of PDX-1 in tumorigenesis is evidenced by its overexpression in a variety of human cancers including pancreatic neuroendocrine tumor (PNET) [7,8,9,10,11,12,13] and by the significant correlation of PDX-1 overexpression with the pathological parameters of cancer patients (e.g., metastasis and histological grade) [9,14].