Extradomain B of fibronectin (ED-B)

Extradomain B of fibronectin (ED-B) is an alternatively spliced type III domain of the fibronectin glycoprotein, rarely expressed in adult tissues but highly upregulated during embryonic development, wound healing, and especially in tumor angiogenesis and various cancers[1][4]. ED-B is a 90–91 amino acid insert, structurally characterized by two antiparallel β sheets and an acidic surface, that confers unique adhesive properties to the fibronectin molecule and alters its structural conformation[1][3]. It is frequently referred to as an "oncofetal marker" due to its high expression in fetal tissues and tumors[3][7]. ED-B provides selective binding sites for specific anti-ED-B antibodies (such as L19), enabling targeted therapeutic and diagnostic strategies in oncology, including imaging of tumor vasculature and delivery of immunotherapeutic agents[3][7]. Its restricted expression pattern and key role in pathological angiogenesis make ED-B an attractive and validated therapeutic target for cancer diagnosis, treatment, and patient stratification[2][3][7].

Other names

ED-BEDBExtra domain BEIIIBOncofetal fibronectin domain BFN-EDB

Antibody-based targeting (L19 and related constructs selectively bind ED-B to deliver therapies) Imaging-guided targeting (contrast agents bind ED-B, allowing visualization of angiogenic vasculature) Inhibition or modulation of tumor angiogenesis via blockade of ED-B/integrin interactions