EDB

Fibronectins are high-molecular-weight adhesive glycoproteins present in soluble form in plasma and other body fluids, and in insoluble form in the extracellular matrix (ECM). The extra domain B splice variant of fibronectin 1 (EDB+ FN or EDB) is a non-internalizing ECM protein. EDB is a 91 amino acid type III homology domain that is inserted into the fibronectin molecule by a mechanism of alternative splicing at the level of the primary transcript whenever tissue remodeling takes place. EDB+ FN has been shown to selectively accumulate in the stroma around new blood vessels in tumors and other pathologies, but to be largely absent in normal adult vasculature.