PKD2 and digestive system neoplasm: Firstly, PKD2 is more abundantly expressed in HUVECs when compared to PKD1.29 Only PKD2 knockdown was able to inhibit endothelial proliferation, migration and tube formation in response to serum.29 Azoitei et al. showed that PKD2 is highly expressed in a variety of gastrointestinal tumors.28 In the same study, they showed that depletion of PKD2 in pancreatic tumors inhibited tumor driven blood vessel formation in a model for angiogenesis, as well as in orthotopic pancreatic cancer xenografts.