TFPI2 and pancreatic ductal adenocarcinoma: Recently, studies have shown that TFPI2 is down-regulated in prostate cancer (Konduri et al. 2001), pancreatic ductal adenocarcinoma (Sato et al. 2005), gastric cancer (Takada et al. 2010), non-small-cell lung cancer (Rollin et al. 2005), etc., and is closely related to various malignant tumors progression.