Fibronectin extra domain B (human) (ED-B (sometimes also EDB or EIIIB))

Fibronectin extra domain B (ED-B) is a 91-amino acid domain, generated by alternative splicing of the fibronectin (FN1) gene, and is incorporated into a subset of fibronectin proteins. In healthy adults, ED-B-containing fibronectin is nearly absent, but it is prominently expressed during embryogenesis, tissue repair, and especially in the neovasculature of solid tumors, making it a marker for angiogenesis and an attractive target for tumor imaging and therapy[5][6][1][3]. ED-B enables fibronectin to interact more efficiently with cellular receptors (especially integrins), supporting cell adhesion, migration, and angiogenic processes in the tumor microenvironment[3][1][4]. Antibody-based therapies (notably L19 and derivatives) leverage the tumor-specific expression of ED-B for targeted drug delivery and imaging, with ongoing research and clinical use especially in oncology[5][2].

Other names

Extra domain B of fibronectinED-BEDBEIIIBOncofetal fibronectin domain B

Targeting ED-B with antibodies enables tumor targeting by recognizing neovasculature and tumor stroma, allowing delivery of cytotoxic agents, radionuclides or cytokines specifically to cancerous tissues. Blocking or altering ED-B function may inhibit tumor angiogenesis by disrupting fibronectin-integrin interactions. Marker for imaging and patient stratification in anti-angiogenic therapy.