Ephrin receptor kinase (Eph)

Ephrin receptors (Ephs) constitute the largest known subfamily of receptor tyrosine kinases. They are activated by binding to their membrane-bound ligands called ephrins. Both Eph receptors and ephrins require direct cell-cell contact for activation. The family is divided into two subclasses—EphA and EphB—based on sequence similarity and ligand-binding specificity. Humans express nine EphA receptors (EPHA1–8, EPHA10) and five EphB receptors (EPHB1–4, EPHB6)[2][4]. Eph/ephrin signaling is crucial for embryonic development processes such as axon guidance, tissue boundary formation, cell migration, segmentation, as well as adult functions like long-term potentiation, angiogenesis, stem cell differentiation—and has been implicated in cancer progression[2][4][1]. The ligands for these receptors are also membrane-associated proteins—ephrin-As being GPI-linked while ephrin-Bs are transmembrane glycoproteins[1][5]. The term "Eph" originates from erythropoietin-producing hepatocellular carcinoma cells where the first member was identified[1][2]. Dysregulation or aberrant expression of these kinases has been linked to various diseases including cancers and neurodevelopmental disorders[2]. No specific approved drugs targeting this entire family were mentioned in the search results; however, several small-molecule inhibitors targeting individual members have been explored preclinically for oncology indications.

Other names

Eph receptorEPH family receptor tyrosine kinaseErythropoietin-producing hepatocellular carcinoma receptorEPHA (for subclass A)EPHB (for subclass B)