The hypoxic microenvironment of the tumor promotes the malignant cells to dedifferentiate and express endothelial cell markers such as von Willebrand factor (vWf), vascular endothelial-cadherin, CD31, laminin 5 γ2-chain, and EphA2 resulting in the formation of ‘endothelial cell-like cells’ (Dunleavey and Dudley 2012). The gene discussed is PECAM1; the disease is neoplasm.